32 
BULLETIN 1279, U. S. DEPARTMENT OF AGRICULTURE 
Table 11. — Rural road mileage by types and highway systems as existing January 1, 
1922, and mileage of each type built during 1921 in each State — Continued 
IDAHO 
State roads 
County roads 
Forest roads 
All rural roads 
Type 
Total 
Jan. 1, 
1922 1 
Built 
1921 
Total 
Jan. 1, 
1922 
Built 
1921 
Total 
Jan. 1, 
1922 
Built 
1921 
Total 
Jan. 1, 
1922 
Built ' 
1921 
Unimproved earth 
Miles 
Miles 
Miles 
2 7, 176. 4 
17, 612. 3 
Miles 
3 17.0 
589.5 
Miles 
2, 517. 
245.6 
121.0 
Miles 
Miles 
9, 693. 4 
17, 857. 9 
565.9 
217.2 
2. 536. 5 
73.2 
56.3 
21.7 
11.2 
39.4 
12.9 
13.5 
Miles 
» 17.0 
Partly graded and 
589.5 
Earth to definite 
grade with perma- 
nent drainage struc- 
tures 
4449 
25.1 
598.5 
40.9 
44.6 
85.5 
Sand-clay . 
192.1 
1, 928. 2 
73.2 
44.7 
21.7 
11.2 
22.3 
5.9 
13.5 
35.7 
494.8 
37.7 
8.6 
6.0 
11.2 
1.4 
35.7 
163.5 
9.8 
9.8 
668. 1 
Waterbound mac- 
adam 
37.7 
Surface-treated mac- 
11.6 
6.5 
15.1 
Bituminous macadam 
6.0 
Sheet asphalt 
11.2 
Bituminous concrete. 
17.1 
7.0 
9.9 
5.7 
11.3 
Portland cement con- 
5.7 
7.3 
7.3 
TotaJ 
1, 104. 2 
226.5 
27, 101. 5 
1, 209. 2 
2, 893. 4 
54.4 
31, 099. 1 
1, 490. 1 
i Includes only mileage constructed and taken over by State. 
2 Includes 1,895.8 miles on State system but not taken over by State. 
' New roads laid out but not improved. 
ILLINOIS 
State roads 
State-aid roads 
County roads 
All rura roads 
Type 
Total 
Jan. 1, 
19221 
Built 
1921 
Total 
Jan. 1, 
1922 
Built 
1921 
Total 
Jan. 1, 
1922 
Built 
1921 
Total 
Jan. 1, 
1922 
Built 
1921 
Unimproved earth 
Miles 
Miles 
Miles 
Miles 
Miles 
36, 108. 5 
46, 339. 8 
1,500.0 
84.0 
6, 676. 
2, 603. 2 
125.3 
34.0 
12.4 
142.7 
100.6 
7.8 
Miles 
Miles 
36, 108. 5 
46, 339. 8 
2, 404. 5 
84.0 
6, 747. 1 
2, 618. 2 
138.2 
62.5 
55.8 
1, 534. 1 
225.5 
7.8 
Miles 
Partly graded and 
drained earth 
315.0 
315.0 
Earth to definite 
grade with perma- J 
nent drainage ! 
structures < 312.1 
194.0 
592.4 
12.7 
206.7 
Sand-clay .. 
Gravel 
Waterbound mac- 
adam.. 
8.9 
0.4 
62.2 
15.0 
12.9 
25.2 
28.6 
626.1 
116.1 
15.8 
500.3 
54.0 
60.0 
10.7 
1.0 
11.0 
11.0 
516.5 
54.0 
Surface-treated mac- 
60.0 
3.3 
14.8 
765.3 
8.8 
2.4 
13. 1 
0.7 
106.3 
2.8 
1.7 
Portland cement con- 
crete 
281.7 
3.0 
399.0 
Brick 
16.8 
Wood block... 
Total. 
1, 113. 2 
481.5 
1, 478. 5 
138.3 
93, 734. 3 
963.0 
96, 326. 
1, 582. 8 
Includes only mileage actually constructed and taken over by State. 
