During the year 1917, an appropriation was made by the Highway
Commission for the construction of cinder macadam between Bend and
Lapine. This work was advertised and, proposals were received on August
7, 1917. As the bids submitted at that time were not considered
favorable, all were rejected, and the work was undertaken under the
supervision of the County Court.
This section, which had been graded under a previous administration,
passes through a flat, pine district, with a surface formation of
volcanic ash, which is a very poor road material, roads without
surfacing becoming practically impassable during the summer season.
As no rock or gravel was available for macadamizing, scoria or volcanic
cinder was used, of which material there is an inexhaustible supply
along the right-of-way. This scoria is very light, weighing about 1,700
pounds per cubic yard. It, however, has made an excellent macadam, and
because of its lightness can be handled and placed cheaper than either
rock or gravel. The results are as favorable as if the best pit-run
gravel could have been had.
A total of 18,300 cubic yards of cinder macadam was placed on this
section and twelve and five-tenths miles of completed surface was
secured. The total cost was $20,183.60, giving a unit cost of
approximately $1,600.00 per mile, which is proof of the economy of this
type of construction where volcanic cinder is obtainable.