DUST PREVENTION AND ROAD PRESERVATION, 1914. 29 
TaBLE 20.— Volume and character of traffic on Connecticut Avenue north and south o if 
Bradley Lane. 
North of Bradley Lane. South of Bradley Lane. 
Vehicle. Maximum. Average. Maximum. Average. 
East. | West. | East. | West. | East. | West. | East. | West. 
DSSS ee OO Oe Oe ee 
Loaded 1-horse wagon .......-.-....- 11 25 4 13 20 18 10 9 
Unloaded 1-horse wagon ............- 8 24 3 11 17 20 8 9 
Loaded 2-horse wagon...........--.- 15 103 6 35 32 96 12 28 
Unloaded 2-horse wagon...-.......- 40 79 10 19 83 52 25 10 
Loaded 4-horse wagon...-..-...-.--..- 2 5 0 1 5 5 0 1 
Unioaded 4horse wagon........---.- 2 2 0 0 2 1 0 0 
1-horse pleasure vehicle..........--.-. 7 18 3 8 21 18 8 8 
2-horse pleasure vehicle ..........-..- 3 3 0 1 20 5 2 1 
Rubber-tired horse vehicle. .......... 1 2 0 0 12 14 1 0 
S20 dre OTSe Nata H eee Bese sec sree sacs 8 12 2 3 15 11 3 4 
Motoney close shee sete ic bio saisSeie Se 17 42 4 15 39 33 13 11 
Excessively heavy vehicle........... 3 11 0 1 5 5 1 1 
Motornunabomie eee are eke 23 173 7 54 169 139 60 44 
IMotoTtOmUnIng Cane. seen see fesse cece 137 308 30 129 454 335 151 117 
HUGAGeHeN OLOMOLA Yao see esc Soo eee 12 47 4 20 31 34 19 14 
2 8 17 19 5 8 
Unloaded motordray !-22225-.26..4.. 14 20 
SUPPLEMENTARY REPORT OF EXPERIMENTS AT CHiHVY CHASE, MD., 
1911 PROJECT. 
BITUMINOUS CONSTRUCTION AND SURFACE TREATMENT. 
The original reports of these experiments are given in Circulars 
Nos. 98 and 99, Office of Public Roads, and a supplementary report 
in U.S. Department of Agriculture Bulletin No. 105. The following 
report is based upon an inspection made January 28, 1915, after an 
extended period of cold wet weather. 
Section No.1 (REFINED CoAL TAR—PENETRATION METHOD). 
In the summer of 1914 the surface presented a well-bound but 
rough appearance and gave evidence of considerable wear on the 
stone of the upper course. Therefore, on August 5 a cold surface 
treatment was applied, using a crude on tar of the analysis given 
mm the following table: 
TABLE 21.—Analysis of crude coal tar} used in cold surface treatment of section No. 1. 
RHE CLE OANA ee oh Cer ie eee ay eave Fe A OM ee ere, pS 1. 146 
SD eCRHeMASCOSIUY,. DOC MC OU aU) ose nen Saat a sans o ep toe Hoes lea neem es 5. 0 
LE TBS, CAEN G (CI i al aed or eat Sn pag ae Te aA ee A ge ls ge per cent.. 8.62 
Distillation: Vv Ene Pare 
BIER ss EO A Se RT) VR Sia ce! SMM ni ape Oe Uae eee Opes Per cents 4' a. Or. po. U 
Neusat M COMMU ee tae ee. Scie ges se te Oe dO ena as LEO 
Sceoudsnoht, oils GOP SPOON: ess oe ae eee AE dors iD a) 
learayzovls. (ld 210 pO nse aoa aA ice Fe dots] 22370 2010 
CANO S (2 — lie) reer eee. eee cE Re donee) As oy le 
URC UA Cor hive RO Eo eee es ee eae raceme airs eae eS 5 ee MOA oOo 102. 
TMOG open ace a ie Ae te OR Ee Ta ee eee doe 10020599; 7 
1 Thin fluid. 2 Ammoniacal. 3 Clear. 4 One-third solid. 5 Hard, fairly dull, brittie. 
