Why the Gas Tax is a Lame Duck

How many times have you read a comment that road pricing is unnecessary (the language is usually baser) because you could just raise the gas tax?

How many times have you heard recently that the rising gas prices will end the conversation about congestion pricing?

Maybe this will help drive some of the air out of those arguments.


$4,000 Car-pool Bludgeon

There have been hundreds of thousands of articles, papers and reports in tens of languages about the effects of the major cordon charging schemes of Stockholm, Singapore and London (LCC and WEZ). Surprisingly, the subject remains unexhausted.

Reports about these systems generally claim an instantaneous 10% increase in speed, a 15% decrease in air pollution, a 20% decrease in congestion, and a critical shift in public acceptance from somewhat below 50% to somewhat above. Any variability that you note is due to the lack of a single audit standard and confounding factors or assumptions that change from report to report.

However encouraging the good news, there is also some bad news. Because these cordon-class systems are new, we have not yet deployed appropriate technology. We are over-reliant on a clutter of road-side infrastructure of fixed DSRC and cameras, and we have been limited in scope – so far, we deploy in 20sqkm areas for about 200-400,000 daily car-trips.

With Google as the lazy researcher’s crutch, I worked out some rough, unaudited figures. I neglected Singapore because I could not find all the data I needed to complete the requisite calculations. Accordingly, for each of LCC, WEZ and Stockholm, after-deployment daily trip counts of 130,000, 178,000 and 329,000 meant trip-count reductions of 60,000, 72,000, and 81,000, respectively. Using average cost reports of capital and operating costs combined to estimate an annual cost for the first five years ($239M, $255M, and $91M, respectively – all figures in rough 2007 US dollars), the annual cost of servicing a daily car trip (250 trips) into each of these three cordons was $1835, $1433 and $277, respectively. (Stockholm, a peninsular island, has only a few choke points.)

Far more interesting, however, the annual cost of removing a daily car trip (250 trips) – is $3975, $3542 and $1123, respectively. Of course this is double-dipping; if a city paid to service the trips that remain in the system, the trips that moved to car-pool, bus, bike or telework are the bonus. But the whole point of this exercise is to reduce peak-hour trips, isn’t it?

I looked also at the area-costs of servicing a cordon – roughly $11M, $20M and $4M /sqkm/per annum, respectively, over the first five years.

This contrarian’s back-of-the-envelop accounting method tells us something: relatively small, equipment-heavy cordons – as any city mimicking London would create – are disastrously expensive. We should learn how to reduce the road-side infrastructure by deploying privacy-assured GPS technology rather than continuing to punish our central business districts with high-maintenance crapscapes.


GHG, Transportation and Congestion

This says 40% of America's GHG is from Transportation:
Reducing Greenhouse Gases Through Traffic Management and Smart Growth
Environmental Defense Fund, Michael Replogle, Transportation Director May 21, 2008

But this table says that overall in the largest 100 US municipalities 59% of per capita contribution to GHG is from transportation, and 3/4 of that is from cars (you'll have to do your own math).

AND the companion brief says metro area residents have smaller carbon footprints than the average American:
Shrinking the Carbon Footprint of Metropolitan America
The Brookings Institution, Andrea Sarzynski, Marilyn A. Brown, Frank Southworth May 2008

(page two of their brief says 33% of GHG comes from transportation across the nation)

How come the discrepancies?

If you look closer at the table, taking ratios city-by-city (for example San Francisco's ratio is a bit over 75%), we are seeing the effect of the predominance of the private vehicle as the producer of GHG. Metro dwellers may have a slightly smaller footprint, but that budget is largely spent on their cars. That will be exacerbated by sprawl, congestion, lousy transit, low transit patronage, outsized vehicles, congestion, longer average commutes, diminished walking, poor bicycle paths and congestion.

The point? In America, metro dwellers may have a slightly smaller footprint, but they could have a very much smaller footprint. Furthermore, since these 100 largest metro areas occupy a tiny fraction of the United States, wide-area cordon pricing could make a huge difference.