4 BULLETIN" 463, U. S. DEPARTMENT OF AGRICULTURE. 



pleasure, and the degree of pleasure experienced in driving is largely 

 dependent upon the scenic attractiveness of the road. 



7. Plan to avoid the necessity for subsequent changes in location. 

 Such changes nearly always work hardship on some of those who 

 have built homes along the road. 



The actual procedure of laying out a road should be controlled 

 very largely by the lay of the land which the road is to traverse. 

 Where the country is comparatively level, for example, practically 

 the whole problem, aside from proper drainage, may be to determine 

 a reasonable balance between the desire to avoid unnecessary damage 

 to farming land and the purpose to secure a reasonably direct route 

 over good ground. 



One of the most common problems in laying out a road in level 

 country is to decide between continuing a circuitous route around 

 cultivated fields or along rectangular land lines, and estabishing a 

 new diagonal route across the fields. Tables 1 and 2, showing, 

 respectively, the area in acres occupied per mile by roadways of 

 various width, with other relevant data, and the diagonal distances 

 across rectangles of various lengths and breadths may be of some 

 assistance in these cases. 



Table 1. — Areas occupied by roadways of various widths and cubic yards of 

 surfacing material required for 1 inch loose depth. 



Width of roadway 

 in feet. 



10 



m 



20 



Area 

 in acres 

 per mile 

 of length, 



0.97 

 1.21 

 1.45 

 1.93 



2.42 

 2.90 



Area 

 in square 



yards 

 per mile 

 of length. 



4,693.3 

 5, 866. 6 

 7, 040. 

 9, 386. 6 

 11,733.3 

 14, 080. 



Cubic 

 yards of 



surfacing 

 material 

 required 



for each 1 



inch loose 



depth 

 per mile 



of length. 



130.3 

 162.9 

 195.5 

 260.6 

 325.8 

 390.9 



Width of roadway 

 in feet. 



30 

 36 

 40 

 50 

 60 



Area 

 in acres 

 per mile 

 of length. 



3.63 

 4.35 

 4.84 

 6.05 

 7.26 



Area 

 in square 



yards 

 per mile 

 of length. 



17, 599. 9 

 21,120.0 

 23, 466. 4 

 29,333.3 

 35, 199. 6 



Cubic 

 yards of 

 surfacing 

 material 

 required 

 for each 1 

 inch loose 



depth, 

 per mile 

 of length. 



Table 2. — Lengths of diagonals in miles for rectangles of various lengths and 



breadths. 





Breadth of rectangles. 



Length of rectangle. 



J mile. 



■J mile. 



J mile. 



1 mile. 



miles. 



1§ 



miles. 



1:! 

 miles. 



2 miles. 





0.353 

 .559 

 .789 

 1.037 

 1.274 

 1. 520 

 1.768 

 2.015 



0.559 

 .707 

 .901 

 1.118 

 1.346 

 1. 581 

 1.820 

 2.061 



0.790 

 .901 

 1.060 

 1. 250 

 1.459 

 1.676 

 1. 904 

 2.136 



1.031 

 1.118 

 1. 251 

 1.416 

 1.600 

 1.S02 

 2. 015 

 2.236 



1.274 

 1.346 

 1.457 

 1.607 

 1.767 

 1.952 

 2.150 

 2.356 



1.520 

 1.581 

 1. 677 

 1.S02 

 1. 952 

 2.121 

 2.304 

 2.500 



1.767 

 1.S20 

 1. 904 

 2.015 

 2.150 

 2.304 

 2.475 

 2.657 



2.015 





2.061 





2.135 





2.236 





2.358 





2.500 





2.657 





2.828 







