Edit topic

Updated your discussion topic below.

Subject
Enter a subject for your topic. Maximum 150 characters.
Post Body
Enter your post below.
NOTE:  This thread was orginally entitled: THREAD LOCKED WITH NO EXPLANATION Why does a thread that ran four pages, starting on 2/19, get locked today with no explanation and no obvious reason?  Perhaps it was a technical fluke. I am referring to the Scott Walker thread in the Transit forum.  This is the last post (I quote in blue) by Sam1 responding to another member’s comment about truckers not paying the full cost of truck damage to roads: “I would like a reference to the studies that show trucks cause the amount of road damage claimed or don't pay their fair share of the cost of building and maintaining the nation's highways.   Clearly, heavier vehicles cause more wear and tear on roadways than lighter vehicles.  The key question is whether the truckers pay a fair share of the cost of repairing the incremental damage that they cause.  The American Trucking Assoication, as you might imagine, claims that they do.   I would like to know the methodologies that were used in the studies.  Model assumptions would be critical to the outcomes.  For example, if the studies assume that all 18 wheelers are carrying 80,000 pounds of goods, that would be incorrect.  Many trucks carry far less weight than their rated capacity, i.e. Frito-Lay trucks loaded with potato chips, FedEx trucks loaded with packages.  Many trucks haul low density, high volume, high value goods, which means that they fill up the trailer with heaps of light materials. Studies can be deceptive.  The researchers frequently use simulation models that rely on assumptions that may or may not apply in the real world.  They usually make heavy use of statistical sampling, projecting the results to the population as a whole.  The results of a statistical sample cannot be projected to the population as a single number.  It has to be a range, determine by the sampling construct constraints.  As soon as someone tells me that trucks cause X amount of damage to the highways, I know it is probably wrong.  A single number would only be correct by chance.  Supporters of commuter rail claim that it is far more fuel efficient that cars.  They base their studies on common operating assumptions, load factors, etc.  I question some of the assumptions.  For example, the average load factor on the Trinity Railway Express (TRE) is approximately 33 per cent, although it is near 80 per cent during the morning and evening rush hours.  How is that factored into the studies?  Also, the TRE trains layover at their end points for approximately 25 minutes, pumping heaps of pollution into the environment.  How does that compare with the modeler's assumptions?  It is these kinds of questions that a researcher needs to address, whether it is a commuter rail operation or the damage trucks do to the highways.  Several years ago Dallas Area Rapid Transit (DART) gave me route information for every one of their routes, included the TRE.  When I asked the Vice President of Operations how much each route contributed to a reduction in pollution in the Dallas/Fort Worth Metroplex, he admitted that he could not tell me.     Whoops, I forgot.  What does the damage trucks do or don't do have to do with commuter rail systems?” **** I was just going to respond to the question at the end of his post as the thread got locked, so I will follow up here with my response: The charge that truckers do not pay their fair share of road damage comes up over and over in order to make it appear that rail subsidies are relatively less unfair because road cost is higher than it appears due to the hidden cost of unaccounted-for truck damage.
Tags (Optional)
Tags are keywords that get attached to your post. They are used to categorize your submission and make it easier to search for. To add tags to your post type a tag into the box below and click the "Add Tag" button.
Add Tag
E-mail Subscribe
Check the box below if you want to receive e-mail notifications when replies are made to this thread.

Receive notifications