DUST PREVENTION AND ROAD PRESERVATION. 



17 



tion that small transverse cracks had developed where the grout had 

 broken loose from a course of brick. 



Beginning with March 4, 1912, regular counts of traffic on the Con- 

 necticut Avenue sections were made. The census is taken every 13 

 days for a 24-hour period. A tabulation of the maximum and average 

 of each class of traffic for the second one-year period, or 28 counts, for 

 the period March 10, 1913, to February 24, 1914, is given in Table 19. 

 The east side of the road carries outgoing traffic and the west side in- 

 coming traffic. 



Table 19. — Volume and character of traffic on Connecticut Avenue north and south of 

 Bradley Lane and west on Bradley Lane. 



Vehicle. 



Loaded one-horse 



wagon 



Unloaded one-horse 



wagon 



Loaded two-horse 



wagon 



Unloaded two-horse 



wagon 



Loaded four-horse 



wagon 



Unloaded four- 

 horse wagon 



One-horse pleasure 



vehicle 



Two-horse pleasure 



vehicle 



Rubber-tired horse 



vehicle 



Saddle horse 



Motor cycle 



Excessively heavy 



vehicle 



Motor runabout 

 Motor touring car... 

 Loaded motor dray. 

 Unloaded motor 



dray 



North. 



Maximum. 



East 

 side. 



17 



22 



83 



4 



2 



14 



2 



2 

 5 

 21 



4 



37 



154 



17 



West 

 side. 



17 

 24 

 80 

 26 

 3 

 2 

 14 

 2 



3 



8 

 18 



22 

 35 

 151 

 32 



Average. 



East 

 side. 



West 

 side. 



South. 



Maximum. 



East 

 side. 



22 



29 

 28 

 81 

 4 

 3 

 29 

 5 



3 



11 

 20 



3 

 50 



226 

 19 



10 



West 

 side. 



19 



29 



85 



25 



3 



4 



26 



6 



4 



7 



20 



22 



51 



229 



31 



14 



Average. 



East 

 side. 







25 



130 



10 



West 

 side. 



2 



22 



106 



10 



West on Bradley Lane. 



Maximum. 



East 

 bound. 



West- 

 bound. 



Average. 



East- 

 bound 



West- 

 bound. 



EXPERIMENTS ON ROCKVILLE PIKE, MARYLAND. 

 TARS AND OILS-SURFACE TREATMENT. 



The principal purpose of these experiments was to demonstrate the 

 relative value of several bituminous products commonly used for 

 surface treatment, and to ascertain, by comparative service tests, 

 the relative economy from a maintenance standpoint of cold treat- 

 ment with the lighter products as compared with hot treatment in 

 which some of the heavier products were used. Incidentally, the 

 relative wearing qualities of trap-rock screenings and fine gravel will 

 be practically tested, and on some of the sections where oil was 

 applied, an attempt was made to learn what difference, if any, would 

 result from making the application to a wet and dry road surface. 



41701°— 14 3 



