ROADS AND BRIDGES 



327 



will make a good surface, instead of building up the 

 entire road crust out of the material hauled. 



Quantities of gravel for roads of different widths and depths 



From the New Jersey Road Report is quoted the following 

 table which gives the numbsr of cubic yards of gravel required 

 in the construction of one mile of gravel road of widths varying 

 from 6 feet to 20 feet and depths from 6 to 11 inches. These quan- 

 tities should be multiplied by 11-2 to give the number of cubic 

 yards of loose gravel required to make the depths given below of 

 compact gravel. 



Number of cu. 



yds. in road 



8 in. deep 



782 2-9 

 912 16-27 

 1,042 26-27 

 1,173 1-3 

 1,303 19-27 

 1,434 2-27 

 1,564 4-9 

 1,694 22-27 

 1,825 5-27 

 1,955 5-9 

 2,085 25-27 

 2,216 8-27 

 2,346 2-3 

 2,477 1-27 

 2,607 17-27 



11 in. deep 



6 



7 

 8 

 9 



10 

 11 

 12 

 13 

 14 

 15 

 16 

 17 

 18 

 19 

 20 



9 in. deep 



880 



1,026 2-3 

 1,173 1-3 

 1,320 

 1,466 2-3 

 1,613 1-3 

 1,760 

 1,906 2-3 

 2,053 1-3 

 2,200 

 2,346 2-3 

 2,493 1-3 

 2,640 

 2,786 2-3 

 2,933 1-3 



10 in. deep 



977 

 1,140 

 1,303 

 1,466 



629 

 1,792 

 1,955 

 2,118 

 2,281 

 2,444 



2,607 

 2,770 

 2,933 

 3,096 

 3,259 



7-9 



20-27 



19-27 



2-3 



17-27 



16-27 



5-9 



14-27 



13-27 



4-9 



11-27 



10-27 



1-3 



8-27 



7-27 



1,075 

 1,254 

 1,434 

 1,613 

 1,792 

 1,971 

 2,151 

 2,330 

 2,509 

 2,688 

 2,868 

 3,047 

 3,226 

 3,405 

 3,585 



5-9 



22-27 

 2-27 

 1-3 



16-27 



23-27 

 1-9 



10-27 



17-27 

 8-9 

 4-27 



11-27 

 2-3 



25-27 

 5-27 



Spreading and compacting earth and gravel surfaces. 

 One very important consideration in constructing the 



