58 BULLETIN 586, U. S. DEPARTMENT OF AGRICULTURE. 
Local failures occurred in sections K and L amounting in all to about 
200 square feet. A profile has been run along both sides and along 
the center of the experiments indicating that there has been consider- 
able settlement in the sections where local failures oceurred. It was 
expected that repairs would be made in the spring by cutting out the 
depressed areas, keying the edges carefully and patching with brick 
similar to that used in the original work. 
A traffic census has been taken on this road every 13 days for a 
24-hour period. A tabulation of the maximum and average for each 
class of traffic for the calendar year 1916 is given in Table 62. The 
west side of the road carries south-bound traffic coming from the 
railroad and the east side carried north-bound traffic toward the 
railroad. 
The total cost of each experiment to December 31, 1916, are shown 
in Tables 59 and 63. ; 
TABLE 62.—Volume and character of traffic on Kensington Road north and south of 
Bradley Lane, Janwary 1 to December 30, 1916. 
North. South. 
Maximum. Average. Maximum. Average. 
North | South | North | South | North | South | North | South 
bound. |} bound. | bound. | bound. | bound. | bound. | bound. | bound. 
1 | Loaded 1-horse wagon....-..--- 7 30 3 14 18 17 10 8 
2 | Unloaded 1-horse wagon..-...-- 9 20 3 9 9 16 5 7 
3 | Loaded 2-horse wagon......---- 18 60 4 24 17 58 7 23 
4 | Unloaded 2-horse wagon.....--- 24 30 8 13 49 15 21 4 
5 | Loaded 4-horse wagon....------ 1 a9 Base ser lscocnoes Fae] Leen halen A mae Le eels a 
6 | Unloaded 4-horse wagon. ...---- 1 Ae | Se ael eee eee 1 A Se ees 2S Ae eS 
7 | One-horse pleasure vehicle. ----- 7 21 2 6 12 10 6 5 
8 | Two-horse pleasure vehicle. ---- 1 (| Baamonce samecaad 4 iL-i} 2 = Se CC a as 
9 | Rubber-tired horse vehicle. - - - - 5 a Eee el tasted 5 Bile Se ee ea 
10 | Saddle horse....--..--.--------- 10 11 3 2 15 10 3 3 
Dis | Motorcycles se css seo essen 8 32 2 12 50 39 13 12 
12 | Excessively heavy vehiclel__..- 5 SN Bospeene 1 6 7 1 1 
13 | Motor runabout... a 38 127 12 54 206 143 78 56 
14 | Motor touring car-..- 295 635 83 264 858 711 386 293 
15 | Loaded motor dray-. ae 32 82 fai 51 7 59 43 35 
16 | Unloaded motor dray-.----.-..--- 13 40 2 12 30 24 7 12 
1 Very heavy vehicles, such as carry ore, stone, timber, machinery, etc. 
TABLE 63.—Surface maintenance costs of 1912 experiments at Chevy Chase, Md., to 
December 31, 1916. 
Maintenance cost of experiments. Total cost per square yard. 
Total for 
Experiment No. Area experi- : z 
ments to 1916. Total. consiruc Hainte Total. 
Dee. 31, 4 
1915. 
Sq. yds Cents. Cents Cents 
MS eos ooeaeee , 498 $3525) ee aeeeerne = $3.25 186.6 186. 84 
Deeks ase hsese4 1, 400 7.66 $3.61 11.27 195. 65 80 196. 45 
See eee ee EIae 4,178 3.57 338. 76 342.33 2154.95 8.19 163.14 
QU eee Sees. 1,744 20.50 17.66 38.16 2150. 25 2.19 152.44 
Dee eee ees cette 3,013 22.73 31.01 2142.29 1.03 143.32 
GEE hs SES 2,055 1.77 1.59 3.36 258. 21 16 258.37 
1 In the progress report for 1915 the square yardage of experiment No. 4 included all oil-cement concrete. 
In October, 1916, sections G, H, I, and J were surface treated with bituminous materials and torpedo sand, 
restoring them to their original condition, and reducing the area of the oil cement concrete experiment to 
1,744 square yards, as originally constructed. The area of experiment No. 3, which is now entirely surface- 
treated, is correspondingly increased to 4,178 square yards. 
2 Weighted average price for different sections. 
