bid_time wrote:
Increasing the load by 12.5% increases the road wear by 42% - BULL!!
THERE IS NO STATISTIC TO BACK UP THAT HYPOTHESIS.
"Some Road Planners say the toll is higher". Who are these road planners? The NCAT has a test track in Alabama. These use real world pavements and test them with real world trucks. They use real world tests to ASTM standards, to compute real live data - NOT "some road planners" talking out of his butt with nothing but hot air to back it up.
Not sure about the exact percentages but they look right.
Back in school in our pavement design courses, we reviewed studies done back in the 50's. The govt built test tracks and paid drivers to drive them 24/7 with trucks of various loads.
The common number thrown out is that a fully loaded interstate semi does 10,000 times the damage of a typical passenger car and the relationship increases with the square of the weight, so a truck that is twice the legal limit (Michigan allows that as an example) won't do 20,000 times the damage of a typical car but 40,000 times the damage.
When we design interstate pavements, we don't even consider passenger cars. They are such a tiny percentage of the calculation that they don't matter.
If you want to see an example, find a weigh station (it must be in regular use and that's often not true as cutbacks leave many closed for long periods) and watch the pavement was you go by it. What you often see is a pavement that was in bad shape suddently get visibly better as soon as you pass the exit ramp and as soon as you pass the entrance ramp it goes back to being bad.
Now to take a step back, that doesn't mean the average semi should pay 10,000 times the taxes. Roads need to be repaired and replaced due to two distinct failure mechanisms:
- Heavy trucks beating the snot out of them
- Simple age: If you prohibit any vehilce larger than a smart car and give it 20-30yrs, you will find the pavement starts to show failures. They will be somewhat different in nature but failures none the less (the exact type depends on the pavement type and the environment).
On top of that, the average freeway can accomodate all the trucks in a single lane per direction, easily. It's the multitude of passenger vehilces that create the need for 2,3,4 or more lanes in each direction. If you built and maintained a truck only roadway, you could cut the costs drastically.
Taxes related to trucking should go up from where they are now but passenger vehicles should still make up the bulk.
As far as the idea that consumers will pay more for goods...they already are, it's just that that you will see the direct cost rather than having it hidden in taxes.