EXPERIENCE WITH MOTOR TRUCKS. 
29 
COST OF OPERATION. 
The average cost of operating trucks of different sizes is given in 
Table XXII. The items included are depreciation, repairs, interest 
on investment, registration and license fees, gasoline and oil, and 
tire cost. 
The figures for annual depreciation are obtained from Table XVI, 
and those for repairs from page 24. 
Interest is figured at 6 per cent on the average investment. The 
average investment has been found by the rule : Average invest- 
ment = first cost X 
years of service +1 
This is the generally accepted 
years of service X 2 ' 
method for determining the average investment in equipment where 
a fraction of the first cost is charged off each year for depreciation. 
The interest charge when computed on this basis is slightly greater 
than when computed on one-half of the first cost. 
The registration and the license fees are the averages of those re- 
ported for the year of 1920 by the owners. These fees vary consider- 
ably in the different States. 
The number of miles traveled per year are obtained from Table 
XV, the gasoline and oil costs from Table XVIII, and the tire cost 
from Table XIX. The tire costs used are those for pneumatic tires 
for each size. In no case is the average cost for solid tires more than 
1 cent per mile different from the pneumatic tire costs. 
No charge has been made for taxes, insurance, housing, or for labor 
spent in caring for the truck. However, these charges would ordi- 
narily amount to a very small portion of the total cost of operation. 
Table XXII. — Cost of operating trucks of different sizes. 
Size. 
J-tonand 
f-ton. 
1-ton. 
li-ton 
and li- 
ton. 
2-ton. 
Fixed charges: 
Annual depreciation 
1245 
75 
51 
15 
$158 ' 
75 
34 
12 
$239 
100 
63 
14 
$288 
Annualrepairs 
150 
Annual interest 
73 
Annual registration and license fee 
20 
Total fixed charges 
386 
279 
416 
531 
Miles traveled per year 
3,928 
2,630 
2,570 
2,837 
Fixed charges per mile 
$0. 098 
.024 
.030 
$0. 106 
.029 
.017 
$0. 162 
.030 
.021 
$0. 187 
Gasoline and oil per mile 
.037 
Tires per mile 
.034 
Total cost per mile 
.152 
.152 
.213 
.258 
