Evening star. [volume] (Washington, D.C.) 1854-1972, 1953-02-23
Average U. 5. Road
Far Less Adequate
Than 70 Years Ago

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The average American high
way today is only fractionally
as adequate for today'S traffic
demands as it was two decades
ago.
This statement was made re-
Gently by Commissioner Of Public
Roads Thomas H. Macdonald to
the Association Of State Highway
officials.
It may come as q sur
prise to some motorists that even
with the huge highway expendi-
lures of recent years we seem,
judging from this statement. to
be making progress backward.
Here briefly is the problem as
seen by the Bureau of Public
Roads, which Mr.. Macdonald
heads.
The increase in the total num-
Der of motor vehicles in use has
been so astonishingly rapid. par
ticularly since the war, according
to the bureau, that the increases
in numbers is quite enormously
given as the major cause of cur
rent highway inadequacies and
deficiencies.
Actually, the number of regis
tered vehicles in the United
States now or at any other time
does not represent true picture
of the constantly increasing load
placed upon highways to provide
acceptable transportation Serv-
ices.
During the period from 1921
to 1880, inclusive, when the high
ways were being classified into
systems and when large mileages
OF roads, many of which are yet
In use, were receiving all-weather
Surfacing. there was an average
of 19,920.000 million registered
vehicles.
53,36O,OOO Million Vehicles.
In 1852, there are $500, 900
million registered vehicles. This
represents an increase of 1879
per cent over the 1921-193O aver
age
Yet this increase of 1879 per
cent in the number of registered
vehicles represents but a frac-
ton of the total increase in
highway facilities necessary to
satisfy the demand of traffic.
For one thing, buses and
trucks, especially those with dual
tires. occupy more road space
than a passenger car. Since
buses and trucks have increased
at faster rate than passenger
vehicles, the need for improved
highway facilities has increased
at a faster rate than the in
crease in the numbers of
vehicles indicates.
A dual-tired vehicle in a
highway capacity sense, is equiv
alent to two passenger cars on
the level terrain, to four pas
6enger cars in rolling country
and to somewhere between five
and 10 passenger cars in
mountainous terrain, depending
on particular conditions. AS a
conservative average. each truck.
including both those with dual
and single rear tires, is equiv-
alent to three passenger cars.
So. assuming the average traf-
f1c for the period 1921-1930 as
100 per cent. the increase in the
number of vehicles in 1852 &C
tually is 2S7.5 per cent rather
than 1879 per cent, the bureau
estimates.
Speed and Mileage Increased
But this still does not reflect
the extent of the problem. Speed
and mileage have increased.
making improved design neces-
sary. The bureau figures 1852
average car speed was SO MI h.,
compared to 26 mIp.h. in the
1921-1930 period.
Speed coupled with increased
traffic has meant more and wider
lanes; three-degree curves where
seven-degree curves once were
adequate; stopping sight dis
tances of 500 feet compared to
275 and passing sight distances
of $500 to $500 feet rather
than $50 to 100 feet. and weight
supporting pavement to handle
increased axle loads. For in
stance, 200 out of each 1000
truck loads currently weigh
over $4,000 pounds, weight Of
truck included. Before World
War II only about AZ loads per
thousand ran this high.
The bureau estimates as a
rule Of thumb that increased
numbers Of vehicles. increased
mileage and the growth in the
number of trucks and buses has
imposed an increased service
load on American highways since
1921-1930 in the ratio of l to f.
and that if the effect of too
narrow lanes. too sharp curves,
too short sight distances and
structural deficiencies is taken
into account. roads improved in
the 1920-1935 period are only
one-eighth as adequate to the job
they are supposed to do as they
were two decades ago.