18 BULLETIN 910, U. S. DEPARTMENT OF AGRICULTURE. 
Of course, snow may make even the best of roads impassable for a 
truck, and this must be remembered in interpreting these figures. 
The exact number of men with different kinds of roads and the 
number of weeks they could not use their trucks is as follows: 
Of 187 men with dirt roads only — 
17 were able to use their tracks every week in the year. 
36 were unable to use them for 1 to 4 weeks in the year. 
32 were unable to use them for 5 to 8 weeks in the year. 
38 were unable to use them for 9 to 12 weeks in the year. 
24 were unable to use them for 13 to 16 weeks in the year. 
19 were unable to use them for 17 to 20 weeks in the year. 
21 were unable to use them for 21 weeks and over. 
Of 298 men with roads partly improved — 
62 were able to use their tracks every week in the year. 
68 were unable to use them for 1 to 4 weeks in the year. 
59 were unable to use them for 5 to 8 weeks in the year. 
43 were unable to use them for 9 to 12 weeks in the year. 
30 were unable to use them for 13 to 16 weeks in the year. 
20 were unable to use them for 17 to 20 weeks in the year. 
16 were unable to use them for 21 weeks and OA-er. 
Of 159 men with improved roads only — 
78 were able to use their tracks every week in the year. 
38 were unable To use them for 1 to 4 weeks in the year. 
19 were unable to use them for 5 to 8 weeks in the year. 
16 were unable to use them for 9 to 12 weeks in the year. 
5 were unable to use them for 13 to 16 weeks in the year. 
1 was unable to use it for 17 to 20 weeks in the year. 
2 were unable to use them for 21 weeks and over. 
On the average, there were 10.7 weeks when the men with all-dirt 
roads could not use their trucks, 7.8 weeks when those with part-dirt 
roads could not use them, and 3.5 weeks when those with wholly 
improved roads could not. 
In all, less than 25 per cent of the men found it possible to use 
their trucks every week in the year, and between 35 and 40 per cent 
reported that there were more than 8 weeks during the year when 
they could not use their trucks. About one-half of the men with 
wholly improved roads stated that they could use their trucks any 
time during the year, but only 9 per cent of those with all-dirt roads 
were able to do so, and there were more than 8 weeks during the year 
when oo per cent of these men with all-dirt roads were unable to use 
their trucks. Snow was doubtless the main factor in making the 
roads impassable for the 81 men who have improved roads only, but 
who found there was at least one week during the year when they 
were not able to use their trucks. 
The kind of tires with which the trucks are equipped apparently 
has little to do with the amount of time which they can not be used 
on account of the roads. That there was no apparent relation be- 
tween the character of the roads and the different kinds of tires, and 
