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Re: those "evil" "dirty" trucks
Author: Edward
Date: 09-21-2015 - 20:25
The ratio of damage is even greater than you stated. The damage done to a semi-flexible pavement (asphalt) by an axle goes up as the 4.2 power of the weight on that axle. Let's round that down to 4 and use a 4,000 pound car and a 80,000 pound semi. For simplicity let's use short tons. One short ton = 2000 pounds
The car has two axles with 1 ton per axle, or:
2 * (1 * 1 * 1 * 1) = 2 units of damage. The units are left as an exercise for the student.
The semi has five axles. Assume the load is spread evenly. Uneven loading increases the damage. So 40 tons or 8 tons per axle:
5 * (8 * 8 * 8 * 8) = 20,480 units of damage.
The ratio between the car and the semi is 20,480 / 2 = 10,240 to 1
And that is why it costs so much to build and maintain freeways with heavy truck traffic, and why driving in the slow lane of the Nimitz gives one a free massage.
The car has two axles with 1 ton per axle, or:
2 * (1 * 1 * 1 * 1) = 2 units of damage. The units are left as an exercise for the student.
The semi has five axles. Assume the load is spread evenly. Uneven loading increases the damage. So 40 tons or 8 tons per axle:
5 * (8 * 8 * 8 * 8) = 20,480 units of damage.
The ratio between the car and the semi is 20,480 / 2 = 10,240 to 1
And that is why it costs so much to build and maintain freeways with heavy truck traffic, and why driving in the slow lane of the Nimitz gives one a free massage.
