ROAD BUILDING AND MAINTENANCE 503 



suitable trees, shrubbery, grass, vines and flowers should 

 be encouraged along the roadway, as they add both to the 

 beauty of the road and the value of farms. 



Drainage. As a rule the only ditches needed for the 

 proper drainage of the road can be made by the road grader. 

 Deeper ditches are necessary where the adjoining land is 

 low and level. In the building of culverts care should be 

 taken to make them large enough to handle the overflow. 

 They must also be sufficiently durable to resist the spring 



Concrete road near Detroit. 



freshets and not be injured by the maximum flow caused 

 by storm water. They should have sufficient slope so that 

 the wash will keep them clean. All the spillways should 

 be paved, if necessary, and the outlet and inlet protected 

 by suitable head and wing walls. 



4. The Construction of Earth Roads 



Shaping the road bed. Earth roads should not be 

 made too wide. Twenty-four to thirty feet is sufficient un- 

 less the road is to be macadamized or otherwise permanently 



