Richmond times-dispatch. [volume] (Richmond, Va.) 1914-current, 1920-10-17
FOR SHORT
HAULS
GETTING THE MOST
FROM OUR s800,000,00O
HIGHWAY INVESTMENT


fare than the shortage oc transpor-
,ation. 1t was largely the realiza-
ton OF this fact that caused our Gov
crnment to appropriate some $780,
100000 TO be spent in the course of
the next few years for the improve
mcnt of highways to permit n more
extended use of the motor truck.
In expanding this amount, the
United States is, in reality, buying
Il certain number of ton-miles of
load-carrying ability, or. in other
words. highways, the value Of which
will depend o. the amount OF ma
tcrial that car no transported over
them. The return IN the Investment
Will be determined, not alone by the
type and construction OF the high
ways built. but also by the capacity
and design OF the vehicles operated
over them.
AS n first step toward securing tho
greatest return in Transportation
from the money spent on highway
Improvement, the Bureau of Public
Roads at Washington has conducted
extensive experiments in order to
determine the type of highway which
VIII give the largest number of tom
miles of load-carrying ability per
dollar expended. However, the other
phase of the problem-that OF regu-
iating motor vehicles so as to get
the greatest tonnage transported
with the least damage to the roads
presents much greater difficulties,
since the decision rests, not in the
hands Of centrally located group
of technically informed men. but
with numerous widely scattered leg
islative bodies. The incnectiveness
of this arrangement can be seen by
the fact that methods of restricting
motor vehicles vary widely in all
parts OF the country. While il is
certain that every Legislature pass
ing n law to establish license fees
or restrict traffic does so in an earn
est effort to conserve the roads, there
is strong tendency on the part of
those not fully appraised of real facts
Ito assume that small trucks cause
less road wear than large trucks.
and that they should. therefore. be
favored.
Consider for moment the effect
Of legislation that has favored the
lighter capacity truck. Regardless
OF whether the material is to he
shipped in large or small trucks
the demand for truck transportation
remains the same, as practically
none OF it can be diverted to other
channels. AS a result. when large
unit haulage is discouraged. the same
amount of freight is merely divided
up, among a greater number of
smaller vehicles, running at far
greater speeds and Increasing the
cost OF hauling by 4 very consider
able percentage.
If this decreased the amount of
road wear and permitted our $780,
100000 investment to obtain more
ton-miles of load-carrying ability, il
is possible that the increased cost
would be justified. But this is not
the case. y careful consideration of
the effect clearly shows that 10 sub
stitutc smaller trucks for large ones
unQuestionably increases road wear
TO illustrate = suppose each dollar
spent in highway Improvement as an
arbitrary figure buys 900 ton-miles
of load carrying ability. Bearing in
mind that two kinds of weight travel
over these roadS-wcight of load and
weight of vchiclc-it is obvious that
the dividends on our investment will
be determined by the proportion of
this traffic which Is useful weight
or weight Of load. The ~ ton truck
mas less Than one ton of vehicle
weight for each ton of capacity:
over Nts dollars worth of highway
were oI ~ tons capacity, then that
dollar would provide for 800 ton
miles of useful load TRANSFORMATION,
y '1-ton truck, on the other hand.
ordinarily weighs over tons itself.
ana so IT this size were used entirely.
the same dollars worth of road
would give only 333 ton-milcs of use
full load transportation, as two-thirds
OF the roads carrying ability would
he used in transporting the weight
of the truck.
The design of the vehicle, as we'll
as size, has an important hearing on
the potential returns OF our $500. 600
"eo investment. Certain tests con-
Quoted by the bureau OF Public Roads
ut washington show that road i'm
pact, which is the principal cause of
road wear, does not necessarily in
crease In proportion To the size OF
the truck. but IS governed by the
amount of weight which a truck car
ries below its springs For instance,
4 5h- ton chain driven truck, fully
loaded, delivered only $50 of the
road impact pressure produced by n
3.ton shaft driven truck operating
under the same condition and carry
ing the same tonnage In n
shaft + driven truck. all of the
final driving mechanism is carried
below the springs. and this weight
delivers continual series of direct
solid blows to the road. while in
ohain-drlvcn truck there is no weight
below the springs except that OF the
wheels and comparatively light
axle. That is why 7ia-ton chain
driven truck will produce less road
impact. and consequently less road
wear, than 5-tcn shaft-driycn truck.
And, furthermore. that is why We
hicle design should he considered in
framing Legislation to derive tho
greatest possible bcnent from our
$s00.oo0,0oo highway investment.
Unfortunately. this subject OF gross
weight restriction is too easily mis-