Why stretch a Semi?

[Ken Orme]

In the days before interstates most of the highways in the west were blacktop. The idea then was as the front axel passed over a point it would set up a vibration in the blacktop. With a longer WB most of the vibration would stop before the rear axle passed over the same point. Less damage to the road.

[JAMMER]

Some of it had to do with bridge laws. This is were the load is on the truck and trailer the distance between the wheels and the weight. Ed