- 
6 BULLETIN 136, U. S. DEPARTMENT OF AGRICULTURE. 
radial roads will tend to vary inversely with their number. Plates 
IV, VI, and [X show the distribution of the main market roads in 
three counties. 
ECONOMIC VALUE OF THE MARKET ROAD. 
The service rendered by highways radiating from a town may be 
measured directly by the tonnage which is hauled over them; and 
their economic importance 1s indicated by this tonnage and varies 
directly with it. There are two ways of computing the tonnage of 
traffic on a road: (a) By actual count, and (b) by determining traffic 
areas supplemented with producers’ and merchants’ estimates of 
tonnage. 
The actual count of traffic determines the average number of teams 
hauling produce each day, their loads, and the average distance 
traveled. From the count on a sufficient number of days a close 
estimate of the average annual traffic may be had. 
TABLE 2.—Tvafjic record of seven unimproved roads. 
| ers 
Dee chants’ Reported 
Road Leneth | Lous per pcieee Equiva- | and pro-| Traffic | costs 
No Location.1 aan day, each (nearest lentannual ducers’ area (cents 
ra *g area. mile) ton-miles. | estimates) (acres). | per ton- 
: | (ton- | mile). 
miles). 
1 | Lauderdale County, 
AAs s(2) dees eee 28.3 58 10 367,894 | 228,046 | 154, 432 16.0 
2 | Booneand Story Coun- | 
leeentiess Towa) eesee 45.1 10 2 162, 342 105,662 | 113,521 37.2 
3 | Cumberland and Sa- | 
gadahoe Counties, | | 
WNiGS (@) eesaasoccuseue 32.1 18 4 PP LEN oe Sook 38, 182 23.6 
4 | Leflore County, Miss. | 
8) Jaane pno us aanesaase 24.1 33 7 197,386 | 90,628 | 60,736 36. 2 
5 | Montgomery County, | 
IMG (UD) fener 5.4 21 2 14,044 | 5,892 | 12,531 26.0 
6 | Muskingum County, | | 
OIG) (Oypesanccsasce 20.9 28 6 11S 0265) 1325 7k: 41, 952 28.0 
7 | Jackson County, Oreg | 
ae ea nash tet | 50. 5 | 11 4 51, 810 32,170 73, 881 36.6 
— | eee eee 
Totals and aver- | 
ALES ans ea | 206. 4 26 Hull ssl sile\ O53 eae een 495, 235 29.1 
1 Numbers in parentheses indicate the number of traffic areas. 
From a map, supplemented by field observations, the traffic area 
served by a highway may be determined. This is the area on 
which originates market produce and for which supplies must be 
hauled from market. Ina wheat country, for example, the average 
annual wheat acreage tributary to a highway will determine approxi- 
mately the principal market traffic. Even a rough estimate of the 
traffic area is valuable for determining the relative importance of 
highways and indicates the order in which their improvement should 
be undertaken. It is also an excellent check on traffic count. 
Traffic data for a number of roads recently investigated by the 
