ROADS AND BRIDGES 293 



The greatest difference in the cost per mile of the roads of similar 

 construction is due to the width, one of the roads being 24, another 

 32, and one, practically a street, 70 feet in width. On account 

 of the fact that no charge was made for supervision, or for ma- 

 chinery, the cost of these roads was probably from fifteen to twenty- 

 five per cent lower than would be the case in ordinary practice. 



UNIT COST OF OBJECT-LESSON MACADAM ROAD, SPRINGFIELD, MO. 



The unit cost of the road built under the direction of the Office 

 of Public Roads at Springfield, Missouri, during the year 1904, 

 is given in the following table, and will serve as a type of what 

 can be done in many localities, as the material of which this road 

 was constructed is found in many parts of that region: 



Total Cost 



cost per 



^ 7 . per cubic 



Crushing: day yard 



Average daily output 75 cu. yds. 



4 men loading wheelbarrows and feeding 



crusher, at $1.50 per day $6.00 .08 



5 men operating wheelbarrows at $1 .00 per day 5 . 00 . 066 



1 crusher attendant 1 . 50 .02 



Water wagon \ time, at $3.00 per day 1 .50 .02 



Fuel oil, etc., for engine 2.50 . 033 



Total $16.50 .219 



Hauling: 



Distance of 2 miles. 



This was done by contract at a cost of 40 cents .40 



Preparing subgrade: 



A regular set of men and teams was employed 

 in this work. The charge is therefore 

 made as for crushing and spreading, as 

 they prepared the subgrade for about 75 

 cubic yards each day. 



2 teams, at $3.00 per day $6.00 .08 



4 men, at $1.50 per day 6.00 .08 



Total $12.00 .16 



Spreading stone and binder: 



6 spreaders at $1.50 per day $9.00 .12 



1 team at $3.00 per day hauling gravel for 



binder 3 . 00 .04 



Total ..$12.00 .16 



