Evening star., 1939-10-12

may no longer be applied. We
must consider something else than
mere dimensions. The motor vehicle
is operated by human beings
and does not guide itself, and as
speed increases, human control di-
minishes. The eye and the hand
cannot hold the car to such a mar
row track. The travel lanes must
be somewhat wider to enable the
driver properly to keep in line at
present prevailing speeds, and sight
distances must be somewhat longer
in order that he may maneuver
safely when confronted with
hazards. The curves must be easier
and elevated on the outer side to
enable him to travel around them
without being forced out of the
proper travel lane. Passing dis
tances with clear visibility must
be longer to enable vehicles to pass
when necessary. All these details
are incident to holding down the
physical hazards of driving as
speeds increase. The program of re-
conditioning and betterment does
not indicate failure of highway en-
gineers in the past to build well.
They built to meet as nearly as pos
sible the recognized conditions,
which were, however, rapidly chang
ing. twenty-five years ago the
immediate task was to provide ia
cilities for an entirely new form
of land transportation. There were
no standards to guide the highway
officials any more than there were
standards to guide the manu-
facturers of the early motor We
hicles who put dashboards and
whip sockets in the earliest cars.
The motor vehicle of today is the
product of new knowledge and new
requirements. So will be our new
highways.
When the American Association
of State Highway On1cials was Or
ganized Is years ago there were
only about 100000 motor vehicles
in the entire United States. Now
at least five States have more auto
mobiles and trucks within their
borders than the whole country had
in 1914. The rapid increase in the
number Of motor vehicles and the
increased amount of driving done
by cars year after year have COM
PEELED State highway departments
to work on practically an emergency
basis.
Roads to meet the demands of
the new and rapidly growing
method of transportation were so
desperately needed and the high
ways of practically the whole coun-
try were so deficient in both mile
age and quality that there was lit
tie time to make exhaustive studies
even of limited areas when the
first Federal Aid Act was passed.
Correspondingly there was much
less chance of serious error in select
ing routes for improvement. How
ever, at that time, brief studies
were made of the distribution of
population, both urban and rural,
and the quantities or values Of agri-
cultural produce, of mines and for
ests, and of manufactures in each
of the smallest political subdivi-
sions for which data were available.
Routes were selected to connect the
principal centers Of population and
to cross the areas Of greatest pro-
duction. Although this method of
attacking a big problem was di-
rect and highly simplifled, the fact
that probably less than l per cent
of the routes were wrongly selected
justif1es its adequacy for that time.
The fact that highway building in
the United States has always been
led by the demands of existing
trafiic also has guided selection and
greatly assisted in avoiding serious
error.
Little to Guide Builders.
With respect to the type of road
and the details of design, there
was little to guide the road builder
In the premises. The new type of
traffic with tractive effort devel-
oped at the rim Of a wheel rather
than under the hoof of q horse
had produced an entirely new. set
OF conditions.
Most OF the principles now ac-
cepted as standard in road building
have been worked out during the
past Is years. Now that highway
officials in all States know how to
construct roads for practically any
given condition, they remain con-
fronted with even bigger problems
Of an economic nature. Engineering
skill has run squarely into economic
laws.
The big questions now are-How
extensive a system Of roads is
needed to serve the traffic needs Of