_Main Thoroughfares_
[Sidenote:
Width of Thoroughfares]
In considering the economical widths for the main thoroughfares
of a city, so many complex factors are involved that no exact and
indisputable conclusions can be reached; but there are certain facts
and principles that ought to remove such decisions from the realm
of purely arbitrary whim and custom by which they are now generally
settled. Practically every normal main thoroughfare, even of the most
compact type, must provide for car tracks in the middle. On straight
runs, according to the present practice and with the new cars in
Pittsburgh, the width occupied from the outside of one car to the
outside of the other is 17 feet 8½ inches. At that, the cars are
narrower than the modern standard in some other American cities, and
the clearance between the cars is reduced to less than a reasonable
requirement for safety. On curving roads, such as the Pittsburgh
topography often imposes, the space occupied is greater. Without
allowing any clearance on the outside, a space not less than 18 feet,
and preferably more, should be allowed for the actual cars on straight
runs.
In Pittsburgh, the gauge of the car tracks was originally made to
conform to the prevailing local gauge of other vehicles, on the
mistaken theory that it was desirable to have the smooth tracks used
by wagons; and this has resulted in the almost invariable conformity
of the wagon gauge to that of the tracks, regardless of the size or
character of the vehicle. With the added fact that Pittsburgh pavements
are prevailingly bad, and that the form of rail is such that it is
very difficult for a wagon to turn out when it has once got into the
track, the teamsters in Pittsburgh are more inveterate in the habit of
driving in the car tracks, and less ready to turn aside for cars or
other vehicles, than in most cities. The severe and constantly repeated
strain of the horses, which is required to wrench heavily-loaded wagons
free from the tracks, is, in the aggregate, a serious economic loss;
and the delays not only to the street cars but to all forms of wheeled
traffic, caused by the conditions described, are incalculably great.
But even good pavements and the use of a grooved rail would not cure
the trouble in Pittsburgh streets as now laid out, because, almost
universally, there is not sufficient room for a vehicle to pass between
the cars and another vehicle standing or slowly moving next the curb.
In every street, vehicles must be free to stop for loading and
unloading, and on a busy thoroughfare the space next the curb is so
much used in this manner as to become merely a series of sidings into
which slow-moving vehicles can turn from time to time in order to clear
the main passageway. The result of the conditions above described is
that practically the whole wheeled traffic in Pittsburgh streets is
inevitably concentrated on the eighteen-foot width where the cars run.
The extent to which this reduces the average speed of travel and the
total capacity of the thoroughfare has been strikingly illustrated
for Pittsburghers by the contrast of the former sluggish congestion
of traffic on Smithfield Street with the sparse appearance and rapid
movement of the same traffic since the "one-way" regulations have made
it possible to get one free line in each direction for moving vehicles
separate from the cars. The same striking increase in capacity is to be
secured, without the grave inconveniences and drawbacks of the "one-way
street" regulations, where the space between the cars and the curb can
be made wide enough for two lines of vehicles, instead of just enough
for one or for one and a half, as is usual in Pittsburgh.
It is very difficult to determine just what is the most economical
allowance of width. There is much variation in the widths of the
vehicles themselves, and the necessary amount of clearance varies with
the average skill of the drivers and with the effectiveness of the
police control. The width of the line is plainly determined by the
widest vehicles in it rather than by the narrowest. In Pittsburgh the
customary width of the heavier and wider wagons is now controlled by
the practical necessity of fitting the wheels to the railway gauge of
5 feet 2½ inches, and the widths are considerably less than prevail
in New York, Boston, and other reasonably well-paved cities where the
wagons are not fitted to the car tracks. About 7 feet over all is now
the ordinary maximum in Pittsburgh, a few auto trucks and delivery vans
exceeding that figure slightly, and an occasional three-horse team
occupying over 8 feet. In New York and Boston, wagons measuring from 7
to 8 feet from hub to hub are common, and they sometimes considerably
exceed 8 feet.
Just as in the case of steam and electric railway equipment, the
tendency is constantly in the direction of heavier, longer, wider
vehicles, for the sake of the operating economy due to large units;
and, with the steady increase in the use of motor vehicles for business
purposes, this tendency is likely to be greatly accelerated. There
is every reason to expect that motor trucks will gradually increase
in size until a limit is fixed by the public authorities in order to
protect the pavements, and for the sake of standardizing the lines
of travel in relation to the street widths. But, in the interests of
economy of operation, the limit should be as high as practicable,
probably not less than 8 feet.
If 8 feet be allowed for each vehicle, plus only a foot of clearance,
the cars and one row of vehicles on each side, between them and the
vehicles standing at the curb, would require 54 feet between curbs.
A wagon _backed_ up to the curb on a busy street will seriously
discommode travel at that, and the clearance allowed is very small. A
width of 54 to 60 feet between curbs is, therefore, highly desirable in
the main thoroughfares.
As a matter of fact, with the widths of vehicles which now prevail
in Pittsburgh, if standing and slow-moving vehicles are compelled to
keep in contact with the curb, it is possible to keep open a line of
travel on each side of the car tracks, with only occasional blockades,
where the width between curbs is 50 feet, or, at a pinch, even 48 or
47 feet. That is to say, the difference in traffic capacity between a
thoroughfare 50 feet from curb to curb and one 45 feet is enormous;
while the difference between 45 feet and 40 feet is very slight.
Since a main thoroughfare is apt in time to become a retail trading
street, wide sidewalk space is important. It is a common rule to make
the distance of the curb from the property line one-third the width of
the roadway.
A total width of 90 feet, with a 54-foot roadway and 18-foot sidewalks,
is a satisfactory minimum for meeting the practical requirements of an
ordinary main traffic street; a width of 100 feet is preferable, and 80
feet may be regarded as a rather niggardly irreducible minimum.
In this connection it is interesting to note the standard widths
adopted in European cities. The standard in London is 48 feet[5]
between curbs and 80 feet between buildings for secondary avenues, and
100 feet over all for principal arteries; and 140 feet over all is
proposed for two great main arteries, the cutting of which, through
the midst of the city, is being considered. In German cities of the
second size, such as Leipzig, Frankfort and Hanover, the standards are
as follows: for strictly local streets, 33 to 47 feet; for secondary
thoroughfares, 50 to 80 feet, and for main thoroughfares, 85 to 118
feet. A Prussian law, in force since 1875, and apparently drawn up to
meet the requirements of Berlin with its heavier traffic, requires
the following dimensions for the laying out of new streets and for
the alteration of old ones: local streets, 40 to 65 feet; secondary
thoroughfares, 65 to 95 feet; main thoroughfares, over 95 feet.[6]
[Sidenote:
Special Types of Thoroughfares]
[Illustration: Park treatment of hillside street junction at Stuttgart]
The above considerations apply only to the ordinary main thoroughfares
of normal character. In most of the great cities of the world, there
has been a considerable development of special thoroughfares of much
greater width, including, for example, locations for transportation
lines (surface or elevated), on separate rights of way decorated with
trees; and including tree-shaded promenades and garden strips. These
have usually been laid out in suburban sections before they were much
built up; or, if within the built-up districts, on the sites of old
fortifications, canals, or other abandoned engineering works. The
latter opportunities are lacking at Pittsburgh, except in connection
with the river banks. In the suburban localities of Pittsburgh, so
much of the available building land is topographically divided into
narrow strips that it would be cut to pieces in an exceptionally
uneconomical manner by any boulevards, of the type usual in flatter
cities, where a substantially uniform width of 150, or 200, or 300
feet is not infrequently carried through for considerable distances.
As a general rule, any width to be secured for esthetic purposes in
connection with Pittsburgh suburban thoroughfares, over and above that
needed for handling the expectable future street traffic, must not be
in the form of a general and continuous widening. But occasional pieces
here and there may be taken for park purposes, as, for instance, a
steep sidehill adjacent to the line and unavailable or difficult for
building. Or a narrow ridge, on which the thoroughfare runs, may have
at some point so little available building land fronting upon it that
the whole can reasonably be parked for a short distance, thus keeping
open the distant views.
[Illustration: Public resting place and outlook spot on a one-sided
hillside street in Heidelberg]
[Illustration: Section showing one type of hillside street]
There are two special forms of street, developed here and there in
hilly cities all over the world, of which Pittsburgh needs to take
account in its suburban development. In many instances, and for long
distances, existing suburban thoroughfares that must be enlarged and
improved, and others that must be laid out, are compelled to run along
the face of hills so steep that a street of level cross section,
even though limited to 80 feet, would leave the land on one or both
sides so far above or below the grade as to destroy its value for
building purposes. In such cases it is often practicable to make use of
one-sided streets or two-level streets. The former are designed to give
accessible frontage on one side only, usually the uphill side. The
property on the opposite side is reached by the next street, which is
laid out correspondingly nearer in order not to make the lots too deep.
The width of such a one-sided street may be curtailed without reducing
its thoroughfare capacity because it is freed from local business
all along one side. Bluff Street, though not a thoroughfare, is an
excellent Pittsburgh example of the one-sided street, and illustrates
the great attractiveness which such streets often possess. In a
two-level street a longitudinal bank, or retaining wall, is introduced
in the middle so as to adapt it to the topography and bring each
half of it nearer to the natural surface where the abutting property
fronts upon it. Such a street must normally be wider than a single
thoroughfare of the same capacity, the saving in construction and in
the development of abutting land more than counterbalancing the cost of
extra width.
[Illustration: Section of a two-level street at Zurich, Switzerland.]
Widths for outlying thoroughfares in a district like Pittsburgh,
therefore, cannot be determined by any general rule. Each must be laid
out as a problem by itself, the principal objects in each problem being
to select a tolerably direct line on reasonable gradient, and so to
fix the side lines of the location that it shall be possible to meet
the immediate needs by constructing an economical suburban road, where
it does not already exist, and ultimately to convert it into an ample
urban thoroughfare with the minimum of cost and inconvenience.
[Sidenote:
Widening Old Streets]
Whatever radical changes may be made to improve the present or
safeguard the future condition of the thoroughfare system in regions
that are now rural, there remains a huge problem within the district
where the street system has already crystallized into substantially its
final form. Here increased capacity can, for the most part, be secured
only by local improvements and widenings of existing thoroughfares.
Fortunately, the building up of the street frontage with solid blocks
of stores, apartments, and business structures, has at most points
followed rather slowly after the earlier wave of detached dwelling
houses, and a large proportion of the streets which are destined to be
the main arteries of the huge future city are still lined by buildings
which are set back at various distances from the street, leaving
front dooryards between them and the sidewalk. Outside of the down
town district, and a limited area in East Liberty, it is possible,
therefore, to provide for the ultimate widening of these streets
without the destruction of many valuable structures, _provided the
preliminary steps are promptly taken_.
As traffic increases and the lots come to be used for business
purposes, such a set-back becomes inconvenient and undesirable, and
one by one the buildings are either extended to the sidewalk by new
additions, or new buildings are erected on the sidewalk line. The
reason for this change is not usually that additional lot depth is
required, for often considerable yards are left unoccupied at the rear,
but is simply that on a commercial street the buildings need to be as
close to the stream of traffic as possible; and since the individual
lot owner cannot move the street as a whole up to his building, he has
to extend or move his building to the street. His immediate purpose is
thus served, and ultimately the whole row of buildings is similarly
advanced in response to changed conditions. But at just about the
time when this process is fully completed, the volume of traffic
flowing over the street is apt to have become so great that everybody
recognizes the street to be too narrow for the increased traffic it
has now to carry. If the case is a bad one, the inconvenience due to
overcrowding the traveled way will in time reach a point where, in
spite of the great cost of such an operation, the buildings all along
one or both sides of the street have to be destroyed and a new building
line established--it may be on the very line where most of the original
buildings stood before increasing traffic began to offer inducements to
move them forward to the sidewalk. Indeed, it may be said as a general
rule that on any street where the buildings are set back from the
sidewalk line the very advancement of a few buildings to the sidewalk
line is a sign which points directly to the growth of travel and
indicates that ample width will soon be needed in that thoroughfare.
As soon as these conditions appear, it is time to act. As already
noted, it is not, in most cases, the desire to utilize a greater depth
of lot which leads to the change, but the desire to get next to the
sidewalk and to do away with a front yard which has served its purpose
and is not wanted under the new conditions. If the street is one likely
to have a considerable amount of through travel, it would be reasonable
_at once_ to lay it out wide enough to handle such travel; and the cost
of the land taken for the widening would be charged, at least in part,
to the abutters, for they get, by the change, what many of them already
want and what the rest will soon be wanting--direct frontage on a busy
sidewalk.
A still wiser course of procedure would be to determine on the widening
of these future main thoroughfares before any buildings have been
advanced to the sidewalk line, and to establish building lines far
enough apart to leave room for all probable future requirements;
but to make no physical widening of the street until the growth of
travel--or the demands of the abutters--call for shifting the sidewalks
over to the established building line and enlarging the roadway to
correspond. This is the invariable practice in Washington and in most
well-conducted European cities. It is the plan to some extent in New
York, where just recently the sidewalks of Fifth Avenue have been
moved back against the building line on the space formerly occupied
by stoops, areaways, and dooryards. Pennsylvania Avenue and Sixteenth
Street, in Washington, are both laid out 160 feet wide from building
line to building line, although Pennsylvania Avenue is an important
business artery and Sixteenth Street is a residence street without
heavy traffic and with no commercial business. On the former, the wide
sidewalks are in immediate contact with the fronts of the buildings,
as is proper for a business street, and the roadway, with car tracks
in the middle, is more than wide enough to carry all traffic that
can ever be concentrated upon it. Whereas, on Sixteenth Street, the
traveled portion of the street, including sidewalks and the space for
sidewalk trees, is only 80 feet wide; and the remainder is occupied by
front dooryards 40 feet deep, which the householders are at liberty to
fence and use almost as freely as if they owned them in fee simple. At
the same time all the householders are protected against the premature
action of any individual lot owner who might see a possible advantage
in being among the first to bid for a commercial business by building
a flat-house with stores under it out upon the sidewalk line 40 feet
in advance of the other houses. This is the sort of thing that is
happening every now and then in Pittsburgh on streets where the great
majority of the owners would prefer to have the set-back continued for
some years longer. In Washington this crowding forward cannot be done;
but when a reasonably large proportion of the owners on any street,
or any block of a street, are ready for the change, the front yards
are abolished and the sidewalk is moved over into contact with the
buildings. If a single owner wants to put in a store long before his
neighbors are ready to give up their front yards and long before the
City is ready to widen the street to increase its traffic capacity, he
is of course at liberty to do so; but he must not move forward of the
general building line. What he usually does is to abolish his own front
dooryard and substitute an extra wide piece of sidewalk paving in place
of it, sometimes using the space for outdoor stands, or show cases,
to attract trade. He may even be permitted to erect light temporary
structures, such as awnings, on the space between his main building and
the present sidewalk line, under which, in good weather, he can do a
very good business.
There is, then, one course of action which overshadows, in permanent
importance and in urgency, all other things that Pittsburgh could do at
the present time for the improvement of its main thoroughfare system.
That is to establish new building lines, at a suitable distance apart,
along all of its present and prospective main thoroughfares which there
is any prospect of being able to widen.
Pittsburgh, in common with other cities in Pennsylvania, has a
remarkable power, which is of the utmost importance in connection
with the intelligent control of its street development, but of which
it has not hitherto taken adequate advantage; a power that appears to
be denied to the cities of every other state in the Union, although
effectively used in some other countries. Pittsburgh may legally
lay out a street in anticipation of a future need, and yet postpone
entering upon the land for construction or for opening it to the
public. Until the city legally enters on the street, the owner of the
land has the free use thereof, and he receives payment only when the
opening takes place; but if, in the interim, he shall have erected any
structure within the limits of the proposed street, he will receive no
compensation therefor when the street is opened. Although similar laws
have been declared unconstitutional in other states, this provision
has been sustained in Pennsylvania, and the power has been effectively
exercised in numberless cases since the middle of the last century.
Philadelphia has applied the same principle to street widenings, as for
example in the case of Chestnut Street. The procedure is to define a
building line, set back a certain distance from the street line, and to
permit no new buildings to be erected in front of that line, but to pay
damages only when the power to prevent the erection of a new building
is actually exercised.
The Chestnut Street widening was authorized by legislation which
provided merely that the street should be widened ten feet, without
specifying the procedure or method of awarding damages.[7]
The procedure used in the widening, as above described, had apparently
no other authority than the general acts under which Pittsburgh has
proceeded in laying out new streets.[8] This application of those
acts has been sustained by the courts. If it is held that a specific
extension of the principle of the Act of 1871 to the widening of
Chestnut Street was implied in the ordinance of 1874, under authority
of the Act of April, 1870, and that it is not generally applicable to
widenings, a general act so intending ought to be secured from the
legislature.
In the Chestnut Street case existing buildings covered most of the
space between the building line and the street line, and the exercise
of the power, with the consequent accruement of damages, occurred in
each case only when the original building was torn down by the owner
and he was required to set the new building back to the new building
line.
The same principle is equally applicable to those cases where the
existing buildings are mostly or wholly back of the new building line;
the damages becoming due in such a case only when a building permit
for the erection of a new structure encroaching on the designated open
space is actually withheld.
The advantages of such a method of procedure, in the case of those
highways where all, or nearly all, of the buildings are now set back
from the street and where a widening will ultimately be needed, are
obvious and very great. In a large percentage of cases, where the
street is still mainly residential, the majority of the abutters would
welcome the establishment of a building line for their own protection
from inconsiderate neighbors; just as the majority of people will pay
higher prices for lots in a neighborhood that is protected by properly
drawn restrictions for setbacks, etc., imposed by a land company. In
a great many such cases abutters could be induced to waive any claims
for damages on condition that the building line should be applied to
the whole street. Furthermore, the actual net damages to be paid would
be distributed over a long period, and a considerable proportion of
them, in many cases, could properly be assessed on adjacent benefited
property owners.
When the actual physical widening of the street takes place, through
absorbing the restricted zones on each side of it, the damages for land
taking will be comparatively small, because at that time most of the
abutters will want nothing so much as that very widening, if only to
bring the sidewalks in contact with the fronts of their buildings. But
regardless of its clear financial advantages to the City, in reducing
its total payments for street widening and especially in distributing
the burden of that cost over a long period without running up a large
bonded indebtedness and interest charges, the fundamental argument
for this method of procedure is that it avoids the absolute dead loss
to the whole community resulting from the destruction of valuable
buildings. It is not practicable to avoid this in any other way and
still accomplish the result of widened thoroughfares. Theoretically, it
could be done by a direct widening of all the highways in the ordinary
manner, if it were to be done promptly; but there are comparatively
few cases in which there would be enough immediate advantage in the
increased width to make the proposition attractive; and it is obvious
that any such wholesale immediate action would involve a sudden and
enormous financial burden which it is utterly impracticable for the
City to assume.
If, after the gradual piecemeal process of widening at moderate and
distributed expense has been begun, the City thinks it would prefer
to have the process over and done with promptly, it is just as able
to complete the widening immediately, by wholesale condemnation,
as if the gradual process had never been entered upon. If the City
begins on the gradual process, it can always change to the other when
it feels rich enough, or when the buildings on the old lines have
become few enough; and in the meantime the erection of new and costly
buildings, obstructive to the proposed widening, has been prevented at
comparatively slight expense. If the City does nothing, pending such
time as it can afford to make the widening at a single operation, the
cost of the operation is liable to mount at least as fast as the City's
ability to pay for it.
While the method proposed is peculiarly adapted to handling the
problem of a thoroughfare along which the majority of the frontage is
not yet occupied by buildings standing on the street line, it may be
objected that it is not suitable for widening one that is built up,
like Forbes Street. It is true that the patchwork appearance of such
a street during the process of gradual reconstruction is somewhat
unsightly,--with here and there a wide place where new buildings have
gone up, and between them narrow parts, thus exposing the blank side
walls of old buildings projecting beyond the new ones. Yet in cities
where the sense of civic beauty is far more acute than it generally is
in America, this temporarily ragged condition is accepted as a small
price to pay for the economical and certain accomplishment of a great
permanent improvement.
[Sidenote:
Unified Procedure For City, County and Borough]
It is obvious that the flow of traffic moves regardless of the
artificial boundaries of the city and the surrounding boroughs, and
that if an efficient system of thoroughfares is to be involved for
the Pittsburgh Industrial District it will be necessary to disregard
those boundaries in planning it. This has been done in the preliminary
studies which have resulted in this report, and the necessity for it
must control the form of any permanent organization for preparing
final plans and executing them. If these duties are to be entrusted
to officers of the City, and the city boundaries remain unchanged,
those officers must have authority from the legislature to deal with
territory beyond the boundaries of the city, as is the case in a
limited way in Wisconsin cities.[9]
The simplest and most logical procedure, if the boundaries of the city
and of the boroughs are to remain substantially unchanged, would be to
establish a common agency for dealing with the general problems of city
planning for all of the municipalities and the related parts of the
country outside of them. The Constitution of Pennsylvania apparently
prevents the formation of a special metropolitan board for the
Pittsburgh Industrial District, but general authority might be obtained
under which the County could establish such a board. If the difficulty
should be met simply by extending the boundaries of the city, it is
important that the new boundaries should include not merely those areas
which are now seen to have close physical relations with the city, but
a great extent of territory within which the beginnings of urban or
suburban growth have started, or are likely to start, during the next
generation.
Whether the duty of planning and providing for the main transportation
lines is made a city affair or a county affair, those who are charged
with it should be free to go as far in any given direction as the
demands of the traffic lead them. They should neither be limited by
arbitrary boundaries in those directions where scattering but connected
urban development may reach out furthest from the center, nor
compelled to extend their operations to an arbitrary boundary in those
directions where such development falls short.
SPECIFIC RECOMMENDATIONS
MAIN ARTERIES
[Sidenote:
Penn Avenue Artery]
As noted earlier in this report, one of the two main eastward
thoroughfare routes, from the Point District, must lie along the
flat land between the Allegheny River and the bluff southeast of the
Pennsylvania tracks. Through this bottle-neck must pass the trunk line
(or lines) of one of the largest thoroughfare systems leading from the
down town district of Pittsburgh. At the foot of the Lawrenceville hill
the system branches into two main lines of extension. On the one hand
are Penn and Liberty Avenues, extending, by different routes, through
the Garfield, Bloomfield, Friendship and Shadyside Districts to East
Liberty; and from there connecting directly to Squirrel Hill, Highland
Park, Homewood, Brushton, Wilkinsburg and all points further east.
On the other hand is Butler Street, following the low land along the
river through Lawrenceville to Morningside and Highland Park. Via the
Forty-third Street bridge, this line reaches Millvale and the country
north thereof; via the Sharpsburg and Aspinwall bridges it reaches
Etna, Sharpsburg, Aspinwall, and Shaler and O'Hara townships, and
connects directly with the Freeport Road, the only thoroughfare leading
up the Allegheny River. The trunk line of this system is composed of
two narrow streets, Penn Avenue and Liberty Avenue, the one 60 and the
other 50 feet in width. Even now this accommodation is inadequate,
and, considering the extent of territory served and the increase of
through traffic to be expected as the city grows and the outlying lands
develop, a much greater capacity for general traffic through this
throat will very soon be needed.
There are four different ways in which this greater capacity might be
realized.
In the first place, a new street might be cut through north of Penn
Avenue. Smallman Street, from Twenty-first to Thirty-sixth Street,
already forms a good sized piece of such a thoroughfare. Pike
Street would be its normal extension in town to Eleventh Street,
but, like Try Street near Second Avenue, it has been surrendered to
the Pennsylvania Railroad for a connecting line and spur tracks.
Furthermore, it is very narrow (not over 40 feet) and is difficult to
widen on account of the many industrial plants abutting thereon. The
connections from such a thoroughfare with Penn Avenue, Liberty Avenue
and Butler Street at one end, and with the down town thoroughfares at
the other, are quite indirect; and they could be improved only at great
expense.
The only other place for a new thoroughfare is along Spring Alley,
between Penn and Liberty Avenues. As this whole block is only 220 feet
wide, including the alley, it is obvious that a broad avenue through
the middle of it would leave the abutting property in very uneconomical
shape.
As a modification of this plan, the widening of Spring Alley entirely
on the south side was considered. As this would leave lots 40 feet
or less in depth between the new street and Liberty Avenue, it would
mean the practical destruction of the half-block from Spring Alley to
Liberty Avenue. The remaining strip could be taken as a central parking
space in a wide boulevard thoroughfare, extending from Spring Alley to
the railroad; or Liberty Avenue could be abandoned, and the space, left
between the new street and the railroad, could be used for warehouses
or for business wanting direct railroad connections; or it might be
sold in whole or in part to the Pennsylvania Railroad, for additional
track space. It is obvious that each of these plans cuts up the
property undesirably: the first is not only costly but is extravagantly
wasteful of land in a region where available land is strictly limited
and should therefore be put to its most efficient use: and the other
plans both involve an entire redistribution of the land south of the
new street. They could hardly be executed without powers of "excess
condemnation" for which constitutional authority is lacking.
A third plan would be to widen Liberty Avenue on the north side. There
is no special difficulty in the way of this scheme, and it could
certainly be more easily carried out, and at less cost, than any of the
Spring Alley plans. Merely as a traffic way between two points, Liberty
Avenue widened would be perfectly satisfactory, but several incidental
considerations must be borne in mind. First, the lots on the north side
of the street would be cut at least to 70 and probably to 50 feet,
neither of which is a desirable depth for lots on a main thoroughfare;
and second, the street would have business frontage on one side only.
The latter is an uneconomic arrangement from the point of view both of
the real estate owner and of the City, and the street would be much
less agreeable than if it were separated from the railroad.
The fourth plan would be to widen Penn Avenue. This street is now 60
feet in width, and most of the lots on each side are 100 feet deep,
except for several blocks on the north side where they are about 120
feet. The street is built up solidly on both sides, but scarcely any
of the buildings are new or costly. The property values are almost
uniformly a little higher than on Liberty Avenue. If Penn Avenue were
widened 10 feet on each side, making an 80-foot thoroughfare, the
abutting lots would still be 90 feet or over in depth; and if the
street were made 100 feet wide, the lots would still be 80 feet deep.
Though it might cost somewhat more to widen Penn Avenue than Liberty
Avenue, it is evident that the abutting property would be left in far
better shape, and the benefit to be had from increased frontage value
would be much greater.
After due consideration of each of the above plans, bearing in mind
the cost, the difficulty of carrying it out, and the value of the
result, both as an important main thoroughfare artery and as a local
improvement, it is recommended that Penn Avenue be widened to 100 feet.
If the widening is to be accomplished by the gradual process,[10]
that is by merely establishing the new building lines at the present
time, and by paying damages only when new buildings are set back to
this line, the widening should probably be made on both sides: for
in this way the minimum set-back will be required for individual new
developments and the lots will be left of a good depth on both sides
of the street. But if the widening is all to be made at once, it will
be less costly to make it entirely on the south side. In either case,
the lots remaining will be none too deep, and it is suggested that
ultimately Spring Alley may be abandoned and the opportunity furnished
for deep lots for warehouses and similar purposes, fronting on a large
thoroughfare and having direct railroad connections over Liberty Avenue
in the rear.
[Sidenote:
Forbes Street Artery]
The other eastward thoroughfare system lies south of the Hill District.
From Soho eastward there are two main branches to the system: on the
one hand are Forbes Street and Fifth Avenue, leading through Oakland
to Bellefield, Shadyside, East Liberty, Squirrel Hill, and all points
east; on the other hand is a possible and much-needed thoroughfare
reaching Greenfield, Hazelwood, Glenwood, and Hays, and from there, by
branches and extensions, connecting to Homestead, Duquesne, McKeesport,
and points up the Monongahela and Youghiogheny Rivers, as well as to
the country south in Baldwin, Mifflin, Snowden, and Jefferson townships.
At present the trunk-line of this system (from the Point District past
Soho hill) is composed of three narrow streets, Second Avenue, Forbes
Street, and Fifth Avenue, which all together are no more than adequate
to accommodate the present surface travel. Future developments in the
East End, up the Monongahela, and in the country south of Homestead,
and improved thoroughfare connections with the two latter regions, will
undoubtedly increase the through traffic on these streets to such an
extent that their capacity will soon be taxed beyond its limit. There
can be no doubt that more accommodations will be needed in the near
future.
[Illustration: Section of Second Avenue between Try Street and Tenth
Street Bridge]
At first thought it was hoped that Second Avenue might be improved to
accommodate a reasonable increase in east and west traffic; but the
Baltimore & Ohio Railroad on one side, and several large industrial
plants on the other, present serious obstacles to widening it. A plan
to exchange locations with the railroad was considered, but it did not
appear to offer sufficient advantage to the railroad to tempt them to
cooperate in the matter.
Incidentally, Second Avenue can and should be widened to 80 feet, from
Ross Street to the Tenth Street bridge, thus making a good connection
between the Point District and the South Side.
It remained then to secure the desired street capacity, in some way,
through the valley now occupied by Forbes Street and Fifth Avenue. To
avoid the higher land values on these streets, various schemes were
tried to get a third thoroughfare in this valley, first on the south
and then on the north side, but without success. The indirectness of
line and the seriousness of grade difficulties, coupled with cost
of cutting new connections at either end, more than outweighed the
advantages offered by the cheaper land.
One proposition, however, is worthy of special remark. That was to
cut a new street from Fifth Avenue, near Sixth Avenue, to the end of
Colwell Street, widen the latter, carry it over the Moultrie Street
valley on a high viaduct, skirt around Soho hill, partly above and
partly below Beelen Street, and either join Fifth Avenue at Robinson
Street, or, going over this street, follow along the hillside and meet
the southerly end of Bayard Street. The cost of constructing this line,
the complication of grades with cross-streets (owing to the width of
the new street), and the difficulty of getting good connections with
any thoroughfares leading up the Monongahela, practically put it out
of the question as a solution of the main problem in hand. But it
offers many advantages as a specialized thoroughfare for fast-moving
automobiles for the East End. It is well up on the hill, furnishing,
at times, fine outlooks over the river; the gradient need nowhere be
over 4 per cent, and the line could be easily laid out so as to have
very few grade crossings with other important streets. It is urged that
this route be borne in mind when the demand is felt for another "Grant
Boulevard," south of the Hill.
It remained, then, to consider adequate widenings of Fifth Avenue or
Forbes Street. The former is now 60 feet wide throughout; it is by
far the more important thoroughfare at present, land values are much
higher than on Forbes Street, and new and somewhat costly buildings are
already crowding out the cheap houses of an older generation. Forbes
Street is also 60 feet in width, except near its westerly end where
it is only 50 feet, but the buildings, on the whole, are much less
valuable than those on Fifth Avenue. Lot depths are practically the
same, and so are the street gradients. It is evident, therefore, that
the widening of Forbes Street should be a far less costly undertaking
than the widening of Fifth Avenue.
A thorough study of the possible eastward extensions of Forbes Street
has developed no obstacles to using it as the principal thoroughfare.
By referring to "Outlying Thoroughfare Improvements" below (Sections
11, 14, 15, 16, 17 and 19), it will be seen that a cross connection can
easily be secured at Brady Street to Fifth Avenue--the latter being
the easier street to widen beyond this point, as well as offering
somewhat better gradients. It will also be seen that the thoroughfare
extension to Greenfield, Hazelwood, Glenwood, and eastward, can branch
from Forbes Street (just east of Brady) more easily and cheaply than
it could from Fifth Avenue. Forbes Street, moreover, enters the down
town district at a slightly more central, and, considering the proposed
improvements in the down town district, a more advantageous point.
It is recommended, therefore, that Forbes Street be made the main
artery of this eastbound thoroughfare system, and that it be widened to
100 feet. As in the case of Penn Avenue, the widening should be made on
both sides if done by the gradual process; but if done all at one time,
it should be made entirely on the south side.
[Sidenote:
South Hills Artery]
Between the Point District and the South Hills there is now urgent need
for a thoroughfare connection of adequate capacity and on reasonable
gradients. At present the only access for surface traffic--except
electric cars--is via the Brownsville Road, or South Eighteenth Street,
or the inclines. The two roads are steep, from 7 to 8 per cent, and the
inclines are expensive and of very limited capacity. The South Hills
country is sparsely developed as yet, but, being comparatively free
from smoke and very near to the business district, it offers unusually
desirable opportunities for homes, and it must soon be thickly settled.
The need for a good thoroughfare to this region will then be of far
greater importance even than now.
Only two reasonable ways of securing such a thoroughfare appear. One is
by a new slanting road up the hillside south of the river, much longer,
and so on an easier gradient, than Brownsville Road; the other is by
some high-level bridge and tunnel scheme, such as that proposed by
residents of the South Hills.
The opportunities for a hillside road have been studied with some care,
but the excessive length required to get a reasonable gradient, and
the difficulties and high cost of constructing a wide thoroughfare on
the steep hillside, have proved to be serious drawbacks to all possible
plans for such a street.
[Illustration: Entrance to a thoroughfare tunnel, Stuttgart]
In any thoroughfare scheme to the South Hills, it is reasonably clear
that the end to be attained is the _most direct_ access possible on
_easy gradients_ to the _higher levels_ of the South Hills country. For
it is on the upper levels, the hilltops and the upper slopes, that most
of the present development has taken place; and there can be little
doubt that in the future, even when building space is at a much higher
premium than it is now, the overwhelming majority of the population
will be found on the hills rather than in the narrow valleys.
[Illustration: Thoroughfare tunnel at Budapest]
[Illustration: Panther Hollow bridge--a good-looking viaduct in
Pittsburgh]
There are certain general tendencies which are observable, both in
America and in Europe, in cities which have a large area of hilltop
land separated by deep valleys. The hills are generally preferred for
residential purposes, and the earliest roads or trails often follow the
ridges, plunging down and climbing up again steeply to get from one
ridge to another. The main roads in the second stage of development
are apt to seek the valleys for the sake of good gradients, with a
corresponding development of the most active urban growth in the
valleys and on the lower slopes; the hilltop development being retarded
by lack of transportation facilities. Nevertheless the continued
attractiveness of the uplands slowly builds them up, and as the wealth
of the community grows there is an inevitable tendency to reduce the
obstacles to ready connection between one hill district and another by
raising the levels of the bridges which cross the intervening valleys.
Bolder and bolder viaducts are built, until finally there is a complete
and more or less independent highway system on the upper levels, and
the major part of the residential district comes to be there too.
Obviously, therefore, every opportunity should be utilized to gain
grade, in the approach to the South Hills District, by starting at a
high elevation and wasting no distance in level stretches, if the most
efficient thoroughfare artery to this district is to be secured.
[Illustration: A viaduct in Lausanne, showing how the valleys are
spanned by the main traffic ways]
The bridge and tunnel plan, proposed by residents of the South Hills,
is briefly as follows: to start from Forbes Street, at Sixth Avenue,
and rise steadily to the bluff north of Second Avenue; from here to
rise on a bridge over the river, at a uniform gradient, to the opposite
hill; to pierce the hill by a tunnel, at the same gradient, and reach
the level of the present highways at the junction of Washington Avenue
and Haberman Street. It is proposed also to have a lower deck on the
bridge, which would connect East Carson Street with Second Avenue and
an extension of Sixth Avenue.
This plan has the obvious advantage of starting some 40 feet higher
than any of the present bridge approaches in the down town district,
and at a point from 500 to 1000 feet north of any other feasible
point of departure. Considerable gain is thus made at the very start.
A uniform, uninterrupted gradient is proposed, from Forbes Street
to Washington Avenue, in order to climb the maximum amount possible
with a given distance and gradient. Information furnished us through
the office of Edwin K. Morse shows that the horizontal distance from
Forbes Street to Washington Avenue is 6800 feet and the difference
in elevation between the two points is 260 feet. It follows that a
uniform gradient, from one end to the other would be 3.82 per cent;
this could be reduced to 3.74 per cent by raising the grade of Forbes
Street about 6 feet, a change which is to be desired in connection
with the down town thoroughfare improvements and the Civic Center. At
first sight this gradient seems good for Pittsburgh; but bearing in
mind the distance--over a mile and a quarter--for which this gradient
is maintained without a break, considerable hesitancy is felt about
recommending it for the main artery of a large thoroughfare system. A
gradient of 3.5 per cent should probably be considered a maximum for
such a long climb on a main thoroughfare, and 3 per cent would be far
better. The former gradient could be secured by dropping the southern
end of the tunnel about 16 feet, the latter by dropping it about 50
feet. In either case, the southern end of the tunnel, or its approach,
would be bent westward and extended a little down the valley, north
of Washington Avenue, toward the mouth of the street car tunnel. The
exact amount of reduction to be desired in the tunnel gradient must
be finally determined in conjunction with a careful study of its
southerly extensions based on complete and accurate surveys of the
possible routes. There is no advantage in lengthening one portion of a
thoroughfare to get a 3 per cent gradient if nothing better than 3.5 or
4 per cent can be secured on the rest of the route. The surveys made
for the County Commissioners, under the direction of E. M. Bigelow,
and courteously shown to representatives of the Civic Commission,
unfortunately fail to furnish the needful data, as they do not extend
to the upland districts which are the ultimate objective of the
proposed route.
[Illustration: ROUGH PROFILES OF SOUTH HILLS TUNNEL AND THOROUGHFARE
ROUTES
The high-level tunnel reaches existing streets at Washington Avenue.
From this point is planned a system of thoroughfares, which, if
constructed, would reach all parts of the South Hills. These
thoroughfares are indicated by dashes beyond the junction of the tunnel
with Washington Avenue.
The Bell House, or low-level tunnel is indicated by a dotted line. It
is an approach to the West Liberty Road and would give easy access only
to the territory reached by that road and to other territory in the
nearby valley bottoms.]
[Illustration: The above diagrams show the areas that can be reached
via the low-level and high-level tunnel routes to the South Hills, on a
maximum gradient of 3½ per cent, by hauls of various lengths from City
Hall. The areas are given in the following table:
---------+---------------------+----------------------+---------------------
| |Amount of land sloping| Remaining land
| Total area reached | over 25 per cent | available for use
---------+---------------------+----------------------+---------------------
Length of| | |
haul from| | |
City Hall| | |
---------+----------+----------+----------+-----------+----------+----------
|Low-level |High-level|Low-level |High-level |Low-level |High-level
| route | route | route | route | route | route
---------+----------+----------+----------+-----------+----------+----------
2½ miles | 156 acres|1091 acres| 86 acres| 373 acres | 70 acres| 718 acres
3 miles | 672 " |2710 " | 293 " | 848 " | 379 " |1862 "
3½ miles |2763 " |4877 " |1053 " |1617 " |1710 " |3260 "
4 miles |6329 " |7408 " |1935 " |2449 " |4394 " |4959 "
---------+----------+----------+----------+-----------+----------+----------]
But even without precise data, it is clear that the best permanent
means of reaching those upland districts, whether on one side of
Sawmill Run or on the other, is not by a tunnel debouching in the
bottom of the valley--say at the Bell Tavern. This follows from the
fact that the tunnel _can_ reach a much higher level at a good gradient
and with a shorter distance. And from this higher outlet point a
viaduct high in the air above the Bell Tavern would give direct access
to the uplands of Beechview and Mt. Lebanon and southward, while
streets of easy gradient would reach the uplands east of Sawmill Run.
The high level tunnel, furthermore, will reach all the areas served by
the low level, or Bell Tavern, route, and in addition can reach the
other and more important lands on the hills which _cannot_ be reached
via the Bell Tavern route within a reasonable distance.
The thoroughfare extensions from the southern end of the tunnel are
briefly discussed under "Outlying Thoroughfare Improvements" below. At
its northern end the new bridge would fit admirably into the proposed
thoroughfare system of the Down Town District, main wide streets
extending directly from the end of the bridge approach to the north,
south, east, and west.
Owing to the importance of the South Side as a point for the delivery
of freight, a reasonably direct and easy approach from there to the
new tunnel seems desirable. Freight to be teamed to the South Hills
District seems likely to originate either near the Smithfield Street
bridge, or east of South Seventeenth Street. From the former point, it
is almost out of the question to get an approach of easy gradient to
the mouth of the tunnel, on account of the lack of distance; but it
must be remembered that the inclines will still be available, greatly
relieved by the new tunnel from their present congestion, and further
that freight for the South Hills could easily be shipped to points
from which access to the new tunnel would be easy and direct. From
the latter point, the connection can be secured by climbing over the
railroad on a viaduct, probably along South Twelfth Street, and thence
following the hillside westward on a more or less uniform gradient
to the mouth of the tunnel. An examination of the hillside below the
Brownsville Road indicates that such a street, though somewhat costly,
is not in the least impracticable. It might be best to construct
it with a minimum of cutting by the use of a sidehill viaduct of
reinforced concrete.
With the modifications above suggested the plan proposed by the
residents of the South Hills, for a bridge and tunnel to the South
Hills District, is eminently desirable. It is, therefore, urgently
recommended as the best method of securing an adequate main
thoroughfare artery to this region.
OUTLYING THOROUGHFARE IMPROVEMENTS
The following recommendations are in no sense the result of an
exhaustive study of the main thoroughfare system of the Pittsburgh
District. They comprise only the most desirable improvements noted
during a general study of the outlying branches and connections of
those thoroughfares which concentrate upon the down town district. The
fact that a study undertaken with such a point of view has led so far
afield that it has compelled the investigation of existing and probable
connections so remote as some of those noted below, is, in itself,
evidence of the complexity of the highway problem, and of the fact that
it cannot be dealt with locally, in a piecemeal manner, without great
sacrifice of opportunity.
The improvements are designated in the following text by numbers which
correspond with those on the accompanying folded map of the Pittsburgh
District.[11]
1. _Sixteenth Street Bridge._--The first thoroughfare branch of the
Penn Avenue artery is the Sixteenth Street bridge. Because of its
physical unfitness, and because it is, at present, an unreasonable
interference to navigation, it must soon be rebuilt.[12]
At the time of reconstruction, the railroad grade crossing on each
approach should be eliminated, probably by carrying the street over the
tracks. At the southern end, the grades make such a change very simple.
At the northern end, the separation of grades will be facilitated if
the tracks of the Pittsburgh and Western Division of the Pennsylvania
Railroad can be lowered a few feet. No physical objection to such a
change of track grade is apparent.
[Illustration: Diagram No. 1. Thirty-third Street improvement. Profile
of Liberty Avenue]
2. _Twenty-eighth Street Grade Crossings._--Near Twenty-eighth Street
the tracks of the Allegheny Valley Railroad cross both Liberty and
Penn Avenues at grade. These grade crossings should be eliminated, the
railroad tracks being raised to go over both streets.
[Illustration: Diagram No. 2. Penn-Liberty connection at Thirty-first
Street]
3. _Thirty-third Street Improvement._--At Thirty-third Street on
Liberty Avenue there is a railroad grade crossing. The street should be
lifted over the tracks and the filling extended west to Thirty-first
Street and east to Thirty-seventh Street; in this way the gradient of
the steep portion of the Lawrenceville hill can be reduced from 5.6 per
cent to 4 per cent, which is the present gradient on the rest of the
hill. (Diagram No. 1.) An easy connection should be made with the Penn
Avenue artery at about Thirty-first Street. (Diagram No. 2.) With these
changes the Penn-Liberty line would provide a thoroughfare from the
down town district to the East End with a 4 per cent maximum gradient,
which is easier than can be reasonably obtained on any other line.
The northern end of the Thirty-third Street bridge and the west end
of Ligonier Streets should be raised to meet the new grade of Liberty
Avenue; the bridge will then be about level, and Ligonier Street will
slope between 6 and 7 per cent down to Thirty-fourth Street.
[Illustration: Diagram No. 3. Penn-Liberty Connection at Howley Street.]
4. _Sassafras Street Outlet._--Raising the grade on Liberty Avenue will
seriously interfere with the western outlet of Sassafras Street. But
if this street becomes of sufficient importance--and its location in
the valley close to the railroads suggests a considerable development
of its frontage for freight houses, warehouses or manufacturing--it
will be simple and satisfactory to bring the western outlet to the
junction of Penn Avenue and Butler Street by means of a short tunnel
under Thirty-fourth Street from the south side of Liberty Avenue to the
northwest side of Ligonier Street.
5. _Penn-Liberty Connection at Howley Street._--A connection northeast
from the junction of Liberty Avenue and Main Street to Penn Avenue
will be needed. (Diagram No. 3). This can be secured by widening
and extending Howley Street. Thereby traffic bound for the Garfield
District and east thereof can climb the Lawrenceville hill by the
comparatively easy gradient (4 per cent) on Liberty Avenue, avoiding
the steeper hill (about 5 per cent) on Penn Avenue. This will also
connect with the proposed Bloomfield bridge to Grant Boulevard.
6. _Forty-third Street Bridge._--Butler Street is the main extension
of the Penn Avenue artery up the Allegheny River, and its first branch
thoroughfare is at Forty-third Street. The Forty-third Street bridge,
like the one at Sixteenth Street, must soon be rebuilt.[13] This bridge
connects Millvale and large sections of Shaler and Ross townships with
the Point District via the Penn Avenue artery. The new bridge should be
of ample width and should be high enough so that the approaches can be
carried over the railroad tracks at either end.
7. _Sharpsburg Bridge._--The Sharpsburg bridge is the next important
branch of the Butler Street thoroughfare. It forms the most direct
connection from Pittsburgh proper to the boroughs of Sharpsburg and
Etna and to large portions of Shaler and O'Hara townships. The bridge
should be widened--the present roadway being only 21 feet including car
tracks--and the northern approaches should be improved. (Sections 60
and 61 following.)
8. _Butler Street Improvement._--From a point nearly opposite the
western end of Baker Street east to Haights Run, there is no property
of value for manufacturing, or for dwellings, or stores, between
Butler Street and the railroad which runs below it on the river bank.
The same is true east of Haights Run as far as the Brilliant pumping
station or the present beginning of Beechwood Boulevard. It seems
very desirable that these portions of Butler Street, instead of being
widened merely enough for traffic accommodation, be developed as a
picturesque riverside parkway--a fitting approach to Highland Park and
a continuation of Beechwood Boulevard. This involves the control of the
narrow strip of property between Butler Street and the railroad; though
occasional houses might be allowed to remain therein without detriment
to the effect as a whole. The Bureau of Parks is working along these
general lines, and has already bought many parcels of the land north of
Highland Park between Butler Street and the railroad.
9. _Haights Run Bridge._--The present Butler Street bridge over Haights
Run is of light construction and has a total width of only 17 feet;
this should be rebuilt of ample strength and capacity.
10. _The Aspinwall Bridge._--The Aspinwall bridge, crossing the
river at Six Mile Island from Butler Street to the eastern portion of
Sharpsburg, is narrow (36 feet over all) and is of light construction.
It is so important that it will some day need to be rebuilt of ample
width and strength for main thoroughfare use. At its southern end it
connects (1) with the Butler Street thoroughfare, of which it forms
the northeastern extension, and (2) with a proposed cross-town line
(Section 25 following) up the Haights Run Valley to East Liberty. On
the north it connects directly with Guyasuta and Aspinwall, with most
of the country in O'Hara township, and with the Freeport Road leading
to Claremont, Montrose, Oakmont and all points up the Allegheny River.
This Freeport Road is destined to become _the_ main thoroughfare up
the Allegheny because the precipitous character of the south bank of
the river, and the consequent almost total absence of land suited
to residential or commercial development between Highland Park and
Verona, make the direct extension of Butler Street, as a riverside
thoroughfare, both expensive and impracticable.
[Illustration: Diagram No 4. Forbes Street--Fifth Avenue connection at
Soho]
[Illustration: Diagram No. 5. Fifth Avenue--Center Avenue connection at
Soho]
11. _Forbes Street--Fifth Avenue Connection at Soho._--At Soho the
connection between the Forbes Street artery and Fifth Avenue--the
principal thoroughfare to Bellefield and all points to the east
thereof--is most simply accomplished by splitting the Forbes Street
artery at Seneca Street into two levels, the upper, on the north side,
running on nearly a straight line and gradient to Fifth Avenue, joining
it just west of the school house. (Diagram No. 4.) The lower portion
would become the continuation of Forbes Street, and should be raised
at Brady Street about 17 feet, or so much that the gradient on Brady
Street, up from Forbes Street under the proposed high-level street
to Fifth Avenue, will not be over 6 or 7 per cent. A good gradient
will still be possible on the approach from Forbes Street to the
Twenty-second Street bridge; and the Forbes Street gradient, down from
Seneca Street, will be much reduced. These changes will greatly improve
the means of access to the Twenty-second Street bridge.
On Forbes Street, just west of Craft Avenue, there is a bad gradient
for a main thoroughfare (about 6½ per cent) which is not easy to
improve; but the above cross connection at Brady Street will give a
through line to the East End via the Forbes Street artery and Fifth
Avenue, with a maximum gradient of about 4½ per cent (on the Soho hill).
[Illustration: Diagram No. 6. Ellsworth Avenue extension]
12. _Fifth Avenue--Center Avenue Connection at Soho._--As a main
thoroughfare feeding Minersville and the northern part of the Hill
District, either from the South Side via the Twenty-second Street
bridge, or from the Point District via Fifth Avenue or Forbes Street,
a connection is needed on a reasonable gradient from Fifth Avenue to
Center Avenue through the valley south of Soho hill. Such a street
(Diagram No. 5) could leave Fifth Avenue at Jumonville Street, start
along the location of Wyandotte Street, then curve around the nose
of the hill and follow the hillside on the west of the valley; thus,
by cutting away some of the recent filling at the upper end of the
valley, it could reach Center Avenue at the corner of Soho Street with
a uniform gradient of about 3 per cent. At present there is no way of
reaching this high land on a gradient less than 7 per cent.
The new street shown on the diagram is preferred to the improvement and
extension of Moultrie Street because (1) it gives a better gradient,
(2) it is a more direct approach from the down town district, and (3)
it leaves the bottom of the valley available for enlarging the Moultrie
Street playground.[14]
[Illustration: A one-sided hill-street in Geneva, possessing an
incidental recreative value]
13. _Ellsworth Avenue Extension._--As Fifth Avenue is the principal
thoroughfare to Bellefield, so Ellsworth Avenue becomes its main branch
or extension from Bellefield to East Liberty. This street should not
end at Neville Street, as at present, but should be extended to the
corner of Craig Street and Fifth Avenue. (Diagram No. 6.)
[Illustration: Diagram No. 7. Monongahela hillside thoroughfare--a
typical section]
14. _Monongahela Hillside Thoroughfare._--The thoroughfare requirements
from the Forbes Street artery up the Monongahela River can best be
met by a hillside street, partly new and partly following existing
streets, running substantially parallel to Second Avenue but along
the hillside above the railroad tracks. This thoroughfare would leave
Forbes Street at the bend about 1200 feet east of Brady Street, cross
the little valley (which should be filled north of the new street) and
extend eastward, crossing Bates Run on a viaduct, and using, where
possible, parts of Lawn and Frazier Streets, to the mouth of Four Mile
Run. Thence, by another viaduct, it would connect with Sylvan Avenue,
on the north side of the valley, and follow this street widened to
Hazelwood Avenue; by another viaduct it would cross the Flowers Avenue
valley to Glenwood Avenue and follow the latter widened and partially
regraded to Mansion Street. There it would bend to the northeast, cut
through the plateau land to the next ravine, cross this on a viaduct
and, bending southward again, descend around the nose of the hill to
the Glenwood bridge. So easy a gradient can be obtained on this new
street that it may reasonably be expected to carry nearly all the
through traffic. With proper connections (the most important of which
are described below), it will also take most of the travel to and from
the residential districts lying above it to the northeast.
The location of this street, high on the hillside above the Monongahela
River, presents unusual opportunities incidental to serving its primary
purpose as a main thoroughfare. With an ample roadway for all kinds of
traffic, with trees for shade and decoration, with a broad promenade
overlooking the river and the hills to the south, it would furnish rare
and much-needed facilities for recreation; and, further, it would have
a distinctive character most appropriate to the rugged topography of
the Pittsburgh District. (Diagram No. 7.)
15. _Bates Run Connection._--Starting from the western end of this new
street, the first important transverse street connection would be at
Bates Run. Here a street should be run up the east side of the valley,
not far from the present location of Romeo Street, to the intersection
of Wilmot and Bates Streets, thus reaching the Oakland District.
16. _Greenfield Avenue Connection._--On the southeast side of Four
Mile Run the new thoroughfare will pass over Greenfield Avenue. But
a connection should be made therewith by running a practically level
street, from about the junction point of Sylvan Avenue and the new
thoroughfare, northeast along the hillside adjacent to Greenfield
Avenue until it meets the Greenfield Avenue grade.
17. _Greenfield and Squirrel Hill Extension._--From this point
on Greenfield Avenue a new street should be built running to the
northeast. It would cross the first little ravine on a viaduct, thence
follow the south bank of the Four Mile Run valley, climbing at a
uniform gradient, and join Beechwood Boulevard at the southern end of
the bridge into Schenley Park. This will furnish a direct connection
from the new hillside thoroughfare to the eastern portion of the
Greenfield District and to Squirrel Hill; the maximum gradient will be
only about 3½ per cent instead of about 7 per cent as at present on
Greenfield Avenue.
This new street could be extended, from the point where it joins the
boulevard, underneath the Greenfield Avenue viaduct, along the side of
the valley to the south and up to the higher portions of the Greenfield
District. The gradient of such a street need not exceed 5 per cent.
18. _Hazelwood Grade Crossing._--Although the construction of the
hillside thoroughfare (Section 14 above) does away with the necessity
for widening Second Avenue east of the Tenth Street bridge, Second
Avenue is still an important main line, and all feasible improvements
should be made thereon. One of these is the elimination of the grade
crossing at Hazelwood, and here Second Avenue should probably be
carried under the tracks.
19. _Glenwood Bridge._--The Glenwood bridge becomes a most important
link in the thoroughfare system; it connects Second Avenue and the
proposed hillside line at one end, with Eighth Avenue in West Homestead
and with the mouth of Streets Run at the other. Eighth Avenue leads
up the Monongahela to Homestead, Munhall, Rankin, Braddock, Bessemer,
Duquesne and McKeesport; Streets Run is the starting point of several
important thoroughfare lines into the country south and east. One of
these thoroughfares will undoubtedly be a main line from the city
proper to Dravosburg and points above on the Monongahela River. The
bridge should certainly be widened and the gradients of the approaches
improved, especially that from Second Avenue.
20. _Baum Street Improvement._--Grant Boulevard will always be an
important line to the East End, especially for fast-moving travel. To
improve its outlet eastward from Herron Hill, Baum Street and South
Atlantic Avenue should be connected and extended west to Craig Street.
The connection between the two streets is easily made by cutting
through the corner between Liberty Avenue and Rebecca Street, leaving
a small triangular park. The extension of South Atlantic Avenue will
require a bridge over the Pennsylvania Railroad just east of Morewood
Avenue, a bridge over the Baltimore & Ohio tracks, and the grading and
paving of the street already located west to Melwood Avenue and Craig
Street.[15]
At its eastern end the outlet into Penn Avenue should be improved by
widening Whitfield Street on the east side and by rounding back the
corner of Baum Street and South Highland Avenue.
21. _Center Avenue Improvement._--The junction of Center, Ellsworth and
South Highland Avenues at East Liberty is certain to become a congested
point and to require more ample outlet into Penn Avenue. Several
possible solutions have been considered, but the simplest plan, and
probably in the end the most economical and satisfactory, is to widen
Center Avenue on the south side from South Highland Avenue to Penn
Avenue, cutting off the jog at the latter end. This improvement will
give ample connection with Penn Avenue and the more important streets
radiating from East Liberty. (Diagram No. 9.)