Some representative ESAL values (assumes typical loads for commercial
vehicles)
Vehicle Type ... ESAL Value
Passenger car ........ 0.0008
Urban Transit Bus ... 0.6806
SU2 Truck ............. 0.1890
SU3 Truck ............. 0.1303
CS3 Truck ............. 0.8646
CS4 Truck ............. 0.6560
DS5 Truck ............. 2.3187
TT5 Truck Trailer .... 0.5317
ESAL = damage done by 18,000 lbs on a single axle
Key: SU = single unit; CS = conventional semi-trailer ; DS = Double
Trailer. n = number of axles.
....
Policy Implications:
"When discussing road wear,
cars don't matter:
road damage is effectively caused by trucks"
.....
"Some Simulations
We see:
The number of passages {before road failure occurs} rises steeply with the number of axles
Going from 2 to 4 single axles results in a factor-of-10 increase in road life
The effect is even more strong with tandem axles
Going from 2 single axles to 2 tandem axles quadruples life
Going from 2 single axles to 4 tandem axles is a factor-of-33 improvement
Philip A. Viton () CRP 776 ó Road Wear January 26, 2012 35 / 37
.....
Policy Implications,II
Public policy should provide incentives for truckers to distribute their
loads over as many axles as possible, and to use tandem axles. This
minimizes forces on the road, and hence road wear.
But most roads are operated in precisely the contrary manner: tolls
increase with the number of axles (other things held constant).
Existing policy encourages truckers to minimize the number of axles,
which is completely wrongheaded."
from:
http://facweb.knowlton.ohio-state.edu/pviton/courses2/crp776/776-roads-handout.pdfDiscussing road maintenance fees for cars of any type is orthogonal to the actual cause of road wear.