DUSI PREVENTION AND ROAD PRESERVATION, 19U. 



29 



Table 20. — Valaamt and character of traffic on Connecticut Avenue north and south of 



Bradley Lane. 





North of Bradley Lane. 



South of Bradley Lane. 



Vehicle. 



Maximum. 



Average. 



Maximum. 



Average. 





East. 



West. 



East. 



West. 



East. 



West. 



East. 



West. 





11 



S 



15 



40 



2 



2 



3 

 1 

 8 



17 

 3 



23 

 137 



12 



14 



25 



24 



103 



75 



5 



2 



18 



3 



2 



12 



42 



11 



173 



8 



29 



4 

 3 

 6 

 10 

 

 

 3 

 

 

 2 



4 

 



30 



4 

 2 



13 



11 



35 



19 



1 







8 



1 







3 



15 



1 



54 



129 



20 



s 



20 



17 



32 



S3 



5 



2 



21 



20 



12 



15 



39 



5 



169 



454 



31 



17 



IS 

 20 

 96 

 52 



5 



1 

 IS 



5 

 14 

 11 

 33 



5 



139 



335 



34 



19 



10 

 8 

 12 

 25 

 

 



s 



2 

 1 

 3 



13 

 1 



00 

 151 



19 

 5 



9 





9 









10 





1 





o 





8 





1 











4 





11 





1 





44 





117 





14 





8 







SUPPLEMENTARY REPORT OF EXPERIMENTS AT CHEVY CHASE, MD„ 



1911 PROJECT. 



BITUMINOUS CONSTRUCTION AND SURFACE TREATMENT. 



The original reports of these experiments are given in Circulars 

 Xos. 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 2S. 1915, after an 

 extended period of cold wet weather. 



Section Xo. 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 coal tar of the analysis given 

 in the following table: 



Table 21. — Analysis of crude coal tar 1 used in cold surface treatment of section No. 1. 



Tic gravity-" _ I 1.146 



iflc viscosity, 50 c. c, 50 ° C 5. 



Free carbon per cent. . 8. 62 



Rv By 

 illation: volume, wi 



• per cent.. » 3.5 3.0 



light oils to 1 10° C do.... 3 3. 3 2.5 



do.... ;t .5 .5 



do.... :1 23. 20.0 



Heavyoifc 270 315 C do.... «12.5 L1.3 



Pitch residue do. ..; * 57. 2 62. I 



! .I. ... 100.0 99.7 



i Thin fluid. : Ammunb-il. 'Clear. •One-third olid. i Hard, feirl doll,l) 



