Heavy trucks also just plain screw up the flow of passenger vehicle and light truck traffic on heavily travelled roads. They just take too long to pick up speed, so every time there is a little slowdown, it's magnified several times over as they slow and then painfully accelerate back up to their original speed. And then there's hilly terrain. On my way home I have to go up one fairly long (several miles) and steep incline. Inevitably the rightmost lane is useless due to heavily laden trucks crawling up it at maybe 20 or 30 mph, while the middle lane is slowed down by somewhat lighter or more powerful trucks passing the really slow ones. There's little if any room for additional roadways up that hill, however, so I don't know what solution there is. In general building separate roads for trucks is a very expensive proposition. It would allow us to put all the expense of building and maintaining those roads on the trucking industry however - heavy trucks being a major reason that our roads crumble as quickly as they do. The less expensive asphalt is fine for lighter vehicles, but trucks really need reinforced concrete roads.
"...It [building separate roads] would allow us to put all the expense of building and maintaining those roads on the trucking industry..."
Just wait until you see what would happen to prices for a head of lettuce, gallon of milk, and roll of toilet paper.
~ Blue Jays ~