HIGHWAY BONDS. is: 
and from $400 to $425 per year is the necessary annual charge for 
resurfacing at periods varying from six to seven years. (See foot- 
note 1, p. 12.) The sum of $525 per mile, on an average, should 
therefore absolutely maintain macadam roads if changes and increases 
of traffic are not excessive. It must be understood, however, that 
in many instances where macadam sufficed for the volume and char- 
acter of traffic prior to 1906, it will not withstand the action of the 
motor vehicle traffic which has developed since that time. 
Many miles of ordinary or water-bound macadam road have been 
resurfaced with bituminous materials and many miles of new 
bituminous-macadam road have been constructed. The logical 
maintenance of such highways is a surface treatment with bituminous 
material and rock screenings, clean gravel, or sharp sand. The 
cost of such surface treatment is from 4 to 12 cents per square yard, 
and it may be expected to last from one to three years, according 
to the density of traffic and the success of the application. Theo- 
retically, perfect surface treatment would constitute absolute main- 
tenance for a bituminous-macadam road. Such maintenance is 
seldom or never realized and bituminous-macadam roads doubtless 
require resurfacing at intervals. The cost of such resurfacing is 
not yet known. The average cost for repair and maintenance of 
7,300 miles of highway in Connecticut, Massachusetts, New York, 
New Jersey, and Rhode Island for the year 1912 was about $800 
per mile. A large part of this money was expended for bituminous 
resurfacing and bituminous surface treatment. There is some ques- 
tion whether the expenditure correctly measures the average cost 
of repairing and maintaining bituminous-macadam roads. In the 
State of New York, however, for the years 1911 and 1912 the average 
cost for repair and maintenance was $724 per mile upon a total 
average of 2,861 miles. The annual cost of repair and maintenance 
on Massachusetts State roads for the years 1910, 1911, and 1912 
was, respectively, $642, $647, and $676 per mile for about 850 miles. 
For the most part these figures for New York and Massachusetts 
represent the cost per mile of resurfacing with bituminous material 
and of maintaining bituminous-macadam and water-bound macadam 
roads by surface treatment with bituminous material. It is clear, 
therefore, that $700 per mile is not an excessive estimate at present 
for the annual cost of all repair and maintenance of bituminous- 
macadam roads. 
The cost of maintaining concrete roads is not yet known. It is 
known, however, that great care must be exercised in constructing 
such roads to insure their success. There have been cases where 
such roads began to disintegrate along the wheel tracks in less than 
a year, owing to defective concrete. Sometimes such roads have 
cracked so badly that it was necessary to remove the surface entirely. 
In other instances the necessary repairs have been very expensive. 
