Tuesday, February 15, 2005


Fuel Economy And The Gas Tax

We're now being told that with the average fuel economy of the US auto fleet is increasing so fast, taxes that are levied on fuel consumption (the per-gallon tax assessed by the feds and your state) are becoming ineffective:

The benefits of more gas-efficient cars are obvious, but less gas use means less
gas tax revenue. Less gas tax revenue means less money for road upkeep. Less
money for road upkeep means that you get to drive your nice, shiny new hybrid
over increasingly bumpy and potholed roads.

But wait - isn't is true that the corporate average fuel economy is actually slipping? Um...

With the nation's overall fuel economy slipping for more than a decade, Congress
asked the National Academies to study the effects that CAFE standards have had
over the past 25 years, as well as effects that potential changes to the program
might have.

And since CAFE doesn't include heavy trucks (those with a GVWR over 8500 lbs, such as 3/4- and 1-ton pickups and SUVs), it may very well be that these are dragging the effective fleet fuel economy down even more than the CAFE numbers would suggest, if indeed the sales of heavy-duty light trucks has increased in the past decade (which is certainly the case, as one can see by looking on the streets or new-car lots).

Now, if we go from a straight XX-cent-per-gallon tax to something that also takes into account the number of miles driven, then we've effectively shifted some burden from the lower end of the economy scale up towards the upper end. That would seem unfair for those that bought something like a Prius, since their tax burden decrease isn't quite so significant.

It might be argued that the purpose of this tax is to discourage driving, and not simply the amount of fuel consumed. That becomes interesting if the end goal is to decrease congestion. But two factors play into the amount of traffic that a road can handle - average vehicle speed, and vehicle size. Assuming that average vehicle speed is something we're not going to attempt to increase, then decreasing the vehicle size provides the most straightforward route to decreasing congestion. And if that's the case, then the per-mile tax should thus also include a factor that takes into account the length of the vehicle (width is probably inconsequential since we're not going to fit more than one car width-wise in a single lane of traffic; height perhaps affects traffic flow but that's pretty tough to quantify).

Personally, I think the whole thing is an attempt to decrease the effective tax

Comments: Post a Comment

<< Home

This page is powered by Blogger. Isn't yours?