12 BULLETIN 136, U. S. DEPARTMENT OF AGRICULTURE. 
sive data on the life of modern vitrified brick roads grouted with 
cement mortar are still lacking to fix the average hfe period.* 
The danger of building roads with little attention to anything but 
the surface, with no provision for repair and maintenance, and with 
bonds of excessive term is, however, very serious. Complete returns 
of highway mileage built with local bond issues are not available, but 
there is given in Appendix B (Tables 25 and 26) a list of bond issues 
and mileage constructed with the proceeds where the reports are 
Highways constructed with borrowed money should be strictly 
maintained.? Maintenance is necessary in order to insure to the 
community the maximum economic service by the road and also to 
preserve the investment. The cost of maintenance and repairs must, 
therefore, be studied at the outset. Unfortunately public records 
do not yet present complete data on the cost of either repair or main- 
tenance, except in certain States which have highway departments. 
Well-constructed gravel roads will sometimes sustain several 
years of traffic without showing marked deterioration, even when 
there has been no maintenance. Such roads sometimes even improve 
during the second season; more frequently, however, they show ruts 
or the formation of chuck holes. It can not be expected that the 
average life of a gravel surface will be greater than that of a macadam 
surface. The average interval for resurfacing macadam roads is 
between six and seven years. If a sum equal to two-thirds of the 
original cost of the gravel surface itself is provided for renewals at 
six-year intervals, it should be estimated at from $150 to $250 per 
mile per year. If $30 is then allowed for annual dragging and small 
repairs, the total annual cost of repair and maintenance of gravel 
roads would be from $180 to $280 per mile. The annual cost of 
strict maintenance is sometimes below $30. In Bennington County, 
Vt., during 1912, 175 miles of gravel roads were maintained at a cost 
of $20.70 per mile. The annual cost of maintenance and repair on 
sand-clay roads, including all necessary resurfacing at periodic inter- 
vals, should not be fixed at less than 10 per cent of the original cost. 
The cost of repair and maintenance of water-bound macadam. 
roads has been determined with considerable exactness from Massa- 
chusetts figures and checked by resurfacing charges in other States 
and in Germany. From $100 to $125 per year ordinarily pays for 
necessary small repairs, such as patching, cleaning culverts, etc., 
! For further information as to the life of roads, see Bulletin No. 48 of the Office of Public Roads, U. S. 
Department of Agriculture, ‘Repair and Maintenance of Highways,’’ and Bulletin No. 23 of the U. S. 
Department of Agriculture, ‘‘ Vitrified Brick as a Paving Material for Country Roads.”? These bulletins 
may be obtained from the U. S. Department of Agriculture. 
2 See Bulletin 48, Office of Public Roads, U. S. Department of Agriculture. 
PO anti 5, eal eT; — 
