EARTH, SAND-CLAY, AND GRAVEL ROADS. 3 



public roads will be raised rather than lowered. Due foresight, 

 therefore, should be exercised in working out the location and design 

 of a road, so that later improvements, such as reducing grades, in- 

 creasing the width of the traveled way, or constructing a better sur- 

 face, can be made without the necessity of making expensive changes 

 in the location or otherwise wasting any considerable part of the 

 work already accomplished. 



A few general rules regarding the location and design of public 

 roads may be stated briefly as follows : 



1. Avoid sharp curves in the road, because such curves are a men- 

 ace to traffic. On light grades and level stretches the location should 

 be preferably such that a traveler may see at least 200 or 300 feet 

 ahead from any point on the road, and on steeper grades this dis- 

 tance should be increased if automobile traffic is to be reasonably safe. 

 Where the view is unobstructed and the grade is practically level 

 country roads of ordinary width may be curved to a radius of only 

 about 200 feet without seriously inconveniencing traffic, but to safe- 

 guard against accidents the radius of curves located on grades should 

 be preferably not less than about 300 or 400 feet, even if the view is 

 perfectly open. 



2. Provide ample width for vehicles to pass each other without 

 leaving the traveled way. The question of proper width is discussed 

 on page 11. 



3. Bear in mind that if a road ever becomes of any considerable 

 importance, its users probably will demand that all the steeper grades 

 be reduced to the lowest maximum that would conform to the general 

 topography of the region which the road traverses. The question of 

 grades is discussed on page 11. 



4. Avoid all unnecessary distance. Aside from the advantages to 

 traffic of a short route, each mile of additional road involves a con- 

 siderable extra yearly expense for maintenance, and this alone may 

 warrant the extra expense of shortening the route when the road is 

 constructed, provided that the decrease in distance does not mate- 

 rially increase the steepness of the grades. 



5. Eegard land lines only in so far as this may be done without de- 

 creasing the usefulness of the road or increasing its ultimate cost. 

 The tendency in most rural communities is to locate all new roads 

 along land lines, regardless of the suitability of the route, and this 

 has been responsible for much waste in the past. Not infrequently 

 roads located along land lines have been graded at considerable 

 expense, and abandoned later when the community demanded a more 

 highty improved road with better grades. 



6. Give reasonable consideration to the pleasing features of the 

 location. A large part of the travel on most country roads is for 



