ANALYSIS OF REVENUES ON VARIOUS BASES. 
Table 3. — The relation of road and bridge revenue to mileage, area, 
population, and assessed valuation, 1914 and 1904. 
A study of this table will show that, while the revenue available 
for road purposes increased from $37.01 per mile in 1904 to $98.22 
per mile in 1914 — an increase of 165 per cent — the actual financial 
burden upon the taxpayers did not increase in the same ratio. This 
was due to the fact that property values increased durhig the same 
period to such an extent that whereas the average tax burden per 
$100 of assessed property value was 23 cents in 1904, it had increased 
to only 35 cents in 1914, an increase of 52 per cent, or less than one- 
third the rate of increase in the road fund. 
ROAD AND BRIDGE BONDS. 
Table 4.— State and local road and bridge bonds outstanding 
January 1, 1915. 
These amounted to $344,763,082, comprising $115,324,500 of State 
bonds and $229,438,582 of local bonds. State bonds have been 
issued in California, Connecticut, Idaho, Maine, Maryland, Massa- 
chusetts, New Hampshire, New York, Rhode Island, Utah, and 
Washington, and were authorized in New- Mexico in 1912, but not 
sold until 1915. The constitutions of Kansas, South Dakota, and 
Wyoming prohibit these States from participating in works of internal 
improvement, and consequently, from issuing State bonds. 
ROAD MILEAGE. 
Table 5»— Total and surfaced mileage of roads in the various States, 
as of January 1, 1915, with comparative information, for 1904 and 
1909. 
It will be seen from this table that on January 1, 1915, there was 
in the United States a total of 2,445,761 miles of road, of which 
257,291.54 miles, or 10.52 per cent, were surfaced. This does not 
include the streets in incorporated cities and towns. By comparing 
these figures with those obtained in former investigations, it 
appears that between 1909 and 1914, 66,824 miles of road were 
surfaced. (Fig. 1.) 
ANALYSIS OF MILEAGE ON VARIOUS BASES. 
Table 6 shows the relation of total mileage and surfaced mileage 
to area and. rural population for the years 1904, 1909, and 1914. 
