32 
BULLETIN 910, IT. S. DEPARTMENT OF AGRICULTURE. 
Roughly, about 60 per cent of these trucks are operated by their 
owners, about 30 per cent by the sons of the owners, and about 10 
per cent by hired men. Automobiles are owned on about three- 
fourths of the farms and tractors on about one-fourth of them. It is 
to be expected that the owner of such an expensive machine as a motor 
truck, or any member of his family, would give it a reasonable amount 
of care and operate it with a reasonable degree of intelligence, and the 
fact that automobiles or tractors were owned on a large percentage of 
these farms indicates that most of the operators were more or less 
skilled in the operation of gas engines. That such a large percentage 
of these trucks were operated without any loss of time and were always 
ready for work when needed is very probably partially due to these 
facts. 
COST OF OPERATION. 
The cost of operating trucks of different sizes reported by these 
men is shown in Table XX. The items considered in making up these 
costs are depreciation, repairs, interest on investment, registration 
and license fees, cost of gasoline and oil, and of tires. 
Table XX. — Cost of operating trucks of different sizes. 
Size. 
Mon. 
1-ton. 
1\- and *^„ 
4-ton. 2 ' ton - 
Fixed charges: 
Annual depreciation 
Annual repairs 
Annual interest 
Annual registration and license 1 
Total fixed charges. 
Miles traveled per year. . 
Fixed charges per mile. . , 
Gasoline and oil per mile. 
Tires per mile 
$91 
50 
21 
10 
Total cost per mile. 
S1S4 
75 
45 
15 
$152 $256 $312 
75 100 150 
33 63 I 83 
18 22 26 
172 
319 
278 
441 
571 
3,790 
4,370 
3,660 
3,100 
4,070 
SO. 045 
.021 
.016 
$0,073 
.025 i 
.029 
$0,076 
.027 1 
.016 
$0,142 
.031 
.017 
$0,140 
.038 
.025 
127 
190 
.203 
The figures for annual depreciation are obtained from Table XIV; 
those for annual repairs are obtained from page 26. 
Interest is figured at 6 per cent on the average investment. The 
average investment has been found by the rule: Average in vest- 
ry j vears of service + 1 m , . . , , ,, , 
ment = first cost X ■ 2 = ?>• This is the generailv accepted 
years 01 service X 2 r 
method for deteraiining 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. 
