62 BULLETIN 586, U. S. DEPARTMENT OF AGRICULTURE. 
A traffic census was taken every 13 days for a 24-hour period. The 
maximum and average of each class of traffic for the calendar year 
1916 is shown in Table 62. Each side of the road carried traffic in 
one direction only. 
JAMAICA, N. Y., 1911. 
OIL-CEMENT CONCRETE, OIL-ASPHALT, TAR, AND FLUXED NATIVE ASPHALT. 
The original report of these experiments was published in Circular 
"No. 98, and reports of annual inspections and repairs are given in 
Circular 99, Office of Public Roads, and in Bulletins Nos. 105, 257, 
and 407, U. S. Department of Agriculture. The following report 
relates to the condition of the pavement on January 23, 1917: 
Experiment No. 1 — Oil-cement concrete. — In September, 1916, the 
old bituminous surface was loosened and removed. The concrete 
pavement for about 20 feet on each end of this section was broken 
up and rolled down with a steam roller to about 2 inches below the 
abutting grade. The whole area of this section was then covered 
with a 2-inch surfacing of Topeka asphaltic concrete. 
Experiment No. 2 — -Cut-back oil-asphalt, mixing method. — The east- 
erly 50 feet has been patched considerably and is in bad condition. 
Experiment No. 3— Fluxed native asphalt, mixing method. — This 
section was in good condition except at places where cuts had been 
made for house connections and along the sides where the foundation 
had been poor. The waves in the surface on the north side at the 
east end had become 2 to 3 inches in depth and were lengthening 
westerly. They seemed to have originated from the waves in the 
adjoining section. The seal coat was wearing thin throughout the 
section. 
Experiment No. 4 — Refined coal tar, mixing method. — The tar seal 
coat on the westerly half was worn nearly off. The whole surface 
showed waviness, especially along the north edge for a width of 5 
feet from station 8 to station 9 and for a width of 10 feet on the 
south side from station 8 + 45 to station 9 + 50 where the surface 
has disintegrated in places to a depth of from 1 to 3 inches. The 
asphalt seal coat on the easterly half was becoming thin and worn 
through in several places. Several shallow potholes had formed 
along the north side from station 9 + 50 to station 9 + 65 and the 
disintegration had extended deeper on the south side from station 
10 + 60 to station 10 + 80. In September, 1916, the surface east of 
a house connection near station 10 + 80 was replaced with a 2-inch 
surface of Topeka asphaltic concrete. 
Experiment No. 5 — Cut-back oil-asphalt, mixing method. — In Sep- 
tember, 1916, the surface of this section, except the easterly 100 feet, 
