EARTH, SAND-CLAY, AND GRAVEL ROADS. 61 



drag to compact readily after it is moved, but not sufficiently wet for 

 traffic following the drag to produce mud. 



The principal factor in successfully operating a properly con- 

 structed road drag, provided the condition of the road is favorable, 

 is skill on the part of the operator. Such skill can be obtained only 

 by intelligent experience, and no rules can be laid down which would 

 enable an inexperienced operator to produce first-class results. 



Under ordinary circumstances the position of the hitching link on 

 the draw chain should be such that the runners will make an angle of 

 60° to 75° with the center line of the road, or, in other words, a skew 

 angle of from 15° to 30°. But when dragging immediately over the 

 ruts, or down the center of the road after the sides Have been 

 dragged, it may be found advantageous to place the hitching link at 

 the center of the chain and run the drag without skew. An intelli- 

 gent operator will learn quickly to adjust such details as this, as well 

 as to shift his weight while riding upon the drag in order to make it 

 cut where cutting is desirable, and deposit material where material 

 is needed. 



MAKING REPAIRS. 



If roads of such types as have been discussed are to be maintained 

 properly, they must frequently receive other attention than mere 

 dragging. The side ditches should be kept open and free from vege- 

 tation, the cross drains and culverts maintained in proper condition, 

 and worn places in the surface repaired as fast as they develop. 



The material used in repairing the surface should be the same as 

 that composing the surface and should be put on in such quantity 

 and manner that after it is compacted the surface will be uniform 

 and continuous. Much time and labor can be saved by making re- 

 pairs as soon as needed, because when a bad place once develops in a 

 road it generally will spread very rapidly until proper steps are taken 

 to correct it. 



COST OF MAINTENANCE. 



There are not sufficient cost data available at present to warrant 

 any very definite statements as to the cost of maintenance, but when 

 roads can be maintained largely by use of the drag, as usually is the 

 case with the simpler types of construction, the cost ordinarily is very 

 small. Accurate data kept by a representative of the Office of Public 

 Eoads for road maintenance in Bennington County, Vt., during 

 1912 and 1913 showed that under favorable conditions a road could 

 be dragged at the rate of about 1 mile per hour. This was where 

 the road was comparatively well shaped and only one trip in each 

 direction was necessary. Where more trips of the drag were re- 



