Minimum headways, 60 min. or more; gasoline bus.
This does not mean that existing lines with headways of 71⁄2 to 10 minutes should be scrapped and replaced with the newer forms of transportation. It would not pay to do this until a headway greater than 15 or 20 minutes has been reached.
Length of Haul for Economical Trucking.
—The railroads would not be alone in the benefits due to better roads. Truck lines could be established to care for freight and passenger traffic between farm and station. Here the truck and railroads would coöperate, there would be no competition, for each would be performing a function incapable (or unprofitable) of performance by the other; the net result would be a benefit to the entire community. But most transport lines that are being established come into actual competition with existing railroad lines. Just how far a motor truck may profitably compete with the railway depends, of course, on the relative costs of transportation. Mr. Cabot[162] calculates that twelve miles is the dividing line between motor truck transport and rail transport. He figures the cost of delivery and removal from the railway station at 15 cents per hundred weight, or $3 per ton at each end for terminal charges and that the cost of motor truck haul is at least 50 cents per ton mile. A ton may be hauled, therefore, on truck, 12 miles to balance the railway terminal expense or charge.
A formula might be worked out this way.
| Let | x | = | the number of miles where rail and truck charges just balance; |
| m | = | motor truck charge per ton-mile; | |
| r | = | rail charge per ton-mile; | |
| t | = | terminal railroad charge-cost of collecting and delivery to the railroad plus the cost ofremoval from the railroad. |
Thus motor charge for x miles is mx and railroad charge for same distance is rx + t, equating these,
mx = rx + t.
Solving for the distance traveled,
x = tm - r.