ROADS 



151 



so that the soil which is carried out by the mud that sticks 

 to the wheels may be replaced and the general wear repaired. 

 Width of Earth Roads. The right of way provided in 

 most states for public roads varies from 40 to 66 feet. This is, 

 perhaps, more land than is needed for that purpose, in most 

 instances. It is unusual to improve more than about 36 

 feet of this right of way, making each side ditch about 9 feet 

 wide and the crown proper 18 feet wide. 



Fig. 81. 



A typical condition of an earth road on which the drag has 

 not been used. 



Earth Road Grades. The grade of earth roads may be 

 greater than those of roads surfaced with stone or similar 

 material, because the loads which are hauled on level earth 

 roads are not as great as those usually hauled on hard roads, 

 owing to the fact that the rolling resistance due to the softer 

 road surface is greater. Thus the smaller loads adapted to 

 earth roads may be hauled up steeper grades with the same 



