24 



BULLETIN 105, U. S. DEPARTMENT OE AGRICULTURE. 



off to some extent, yielding a mosaic appearance, but, owing to a 

 fair penetration obtained with tlie material used, the stones are 

 held firmly in place by a matrix of fine stone and bitumen. Experi- 

 ment No. 3 has a more rubbery or corky character than any of the 

 others, and shows some tendency to become muddy during long 

 periods of rain or snow. This tendency is still more pronounced 

 on experiment No. 7, but the surfaces of both experiments soon 

 become smooth and perfect with the advent of dry weather. Evi- 

 dences of frost action and a consequent heaving of the surface were 

 noted between station 164 + 00 and station 167 + 00. Between 

 station 156 + 50 and station 157 + 50 a 24-inch culvert running 

 diagonally under the road broke through. This has been replaced 

 with new pipe, and the road will necessarily be resurfaced over the 

 area involved. The surfaces of experiments Nos. 4, 5, and 6 are in 

 general smooth and firm throughout. There is, perhaps, more 

 unevenness throughout experiment No. 5, owing largely to the fact 

 that the treatment was so interrupted because of the difficulties 

 incident to handling the tank car of foaming material. The surface 

 of experiment No. 6 has picked off in a number of small areas through- 

 out the crown of the road, and will require immediate repair at 

 these points. These defects evidently developed through insufficient 

 protection of the bituminous surface with screenings or gravel. 

 There has apparently been some settlement in the wheel tracks 

 throughout experiment No. 7 and to some extent on experiment 

 No. 6. 



Beginning with June 28, 1913, regular counts of traffic on Rock- 

 ville Pike were made every 13 days for a 24-hour period. A tabula- 

 tion of the maximum and average of each class of traffic for 22 counts, 

 covering the period from June 28, 1913, to March 28, 1914, is given 

 in Table 29. 



Table 29. 



Volume and character of traffic on Rochville Pike at its intersection with 

 Bradley Lane. 



Vehicle. 



Maximum. 



North- 

 bound. 



South- 

 bound. 



North- 

 bound. 



South- 

 bound. 



1. Loaded one-horse wagon... 



2. Unloaded one-horse wagon . 



3. Loaded two-horse wagon . . 



4. Unloaded two-horse wagon 



5. Loaded four-horse wagon.. 



6. Unloaded four-horse wagon 



7. One-horse pleasure vehicle. 



8. Two-horse pleasure vehicle. 



9. Rubber-tired horse vehicle. 



10. Saddle horse 



11. Motor cycle 



12. Excessively heavy vehicle. 



13. Motor runabout 



14. Motor touring car 



15. Loaded motor dray 



10. Unloaded motor dray 



65 

 4 

 4 



22 

 4 

 6 



18 



43 

 5 



44 

 200 



15 

 7 



