DUST PREVENTION AND ROAD PRESERVATION, 1916. 
41 
Table 46. — Analysis of residual asphaltic petroleum * used in surface treatment of 
Bradley Lane. 
Specific gravity, 25°/25° C 0. 993 
Specific viscosity, Engler, 100° C, 50 c. c 13. 5 
Float test at 50° C., seconds 28 
Loss at 163° C, 5 hours, 20 grams, per cent 13. 71 
Float test on residue, 50° C, seconds 151 
Per cent of total bitumen insoluble in 86° B. naphtha. 18. 63 
Per cent fixed carbon 11. 25 
Bitumen soluble in CS 2 (total bitumen), per cent 99. 89 
Organic matter insoluble, per cent 08 
Inorganic matter insoluble, per cent 03 
Total 100. 00 
Table 47. — Materials and cost data for surface treatment in 1916. 
Area treated square yards . . 6, 788 
Quantity of material per square yard: 
Bituminous material gallons. . 0. 195 
Gravel cubic yards. . . 0113 
Cost per square yard (cents): 
Bituminous material 2. 15 
Gravel ♦. 2. 90 
Cleaning surface .28 
Hauling materials .82 
Applying bituminous materials .80 
Applying sand and gravel .42 
Supervision .62 
Total 7. 99 
Table 48. — Surface maintenance costs of 1915 experiments, Bradley Lane, Montgomery 
County, Md.,from Jan. 1 to Dec. 31, 1916. 
Length of 
section. 
Area. 
Cost per square yard. 
Mainte- 
Experiment No. 
Construc- 
tion. 
Mainte- 
nance. 
Total. 
nance cost 
per mile. 
1 
Feet. 
3,614 
200 
Sq. yards. 
6,421 
367 
Cents. 
32.84 
39.42 
Cents. 
}■ 7.29 
Cents. 
40.48 
2 
2 $684. 31 
Table 49. — Volume and character of traffic on Bradley Lane, Jan. 1 to Dec. 30, 1916. 
Twenty-four-hour period. 
Maximum. 
Average. 
East 
bound. 
West 
bound. 
East 
bound. 
West 
bound. 
1 
Loaded 1-horse wagon 
11 
12 
24 
8 
3 
1 
11 
1 
2 
6 
37 
4 
95 
436 
35 
10 
15 
13 
14 
18 
3 
1 
8 
2 
5 
4 
42 
4 
88 
493 
41 
13 
6 
5 
10 
2 
1 
7 
2 
Unloaded 2-horse wagon 
4 
3 
Loaded 2-horse wagon 
6 
4 
Unloaded 2-horse wagon 
6 
ft 
Loaded 4-horse wagon 
1 
6 
Unloaded 4-horse wagon 
7 
One-horse pleasure vehicle 
3 
4 
8 
Two-horse pleasure vehicle 
9 
10 
Saddle horse 
1 
9 
1 
27 
141 
18 
4 
1 
11 
Motor cvcle 
10 
12 
Excessively heavy vehicle 3 
1 
13 
Motor runabout 
33 
14 
Motor touring car 
160 
15 
Loaded motor drav 
24 
16 
Unloaded motor drav 
3 
1 Viscous, sticky fluid. 2 Width of surfacing taken as 16 feet. 
8 Very heavy vehicles, such as carry ore, stone, timber, machinery, etc. 
