New Report on Old Roads Uses Old Assumptions

pirestudy1.jpg

A new report on the costs of aging roads [PDF] has gotten a lot of attention over the past week, with both Transportation Secretary Ray LaHood and the Washington Post touting its conclusion on the danger of "deficient roadways."

On
its face, the report sounds like an argument for prioritizing road
repair and modernization over new construction, which is certain to be
a flashpoint as Congress works on a new federal transportation bill.
But some of the upgrades that the authors suggest rely on outmoded
assumptions about driver safety — not to mention pedestrian safety, a
concept never mentioned in the report.

Here’s an excerpt:

Numerous
solutions — some simple, some complex — could help make the roadway
environment safer for users. These improvements include structural
changes such as adding or widening shoulders, improving roadway
alignment, replacing or widening narrow bridges, reducing pavement
edges or drop-offs, and providing more clear space in the area adjacent
to roadways.

Adding or widening shoulders for bike
lanes or pedestrian paths is one thing, but the notion that driving can
be made safer by widening and straightening roads (or "improving
roadway alignment," as the report puts it) has been debunked by "Traffic" author Tom Vanderbilt, transportation planner Eric Dumbaugh,
and others. In fact, making roads more complex and curvy can often
serve as a deterrent to unsafe driving practices, particularly on urban
streets.

But the report, commissioned by the
Transportation Construction Coalition (TCC), seems to have concluded
that urban areas don’t need to be considered separately from
interstates.

"Although this study did not break
out costs by class of roads, interstate highways are built to higher
safety standards than other roads," the authors state — as if a new
four-lane freeway through Chicago or Brooklyn would be a reasonable
safety-enhancement move.

Roger Henderson, an engineer at
Henderson Consulting in North Carolina, said the report made a solid
attempt to link transportation and public health but made "a critical
mistake" in treating all roads in the same way.

The report seems to argue, Henderson said in an interview, that "federal money should be
spent to cut down trees and move poles away from the roadway. I agree completely when
it comes to interstates, but this is the wrong study to make conclusions in any urban setting."

The report’s sponsorship may have had an effect on its conclusions, Henderson added.
Indeed, the TCC is an alliance of unions and trade groups that — as as the Post succinctly put it — "has a vested interest in funding for road
construction."

Taking
its origins and questionable assumptions into account, however, two
maps in the report tell an interesting tale of the regional toll
exacted by traffic.

The map above depicts road-related
crash costs for every million vehicle miles traveled on state roads,
and the map below depicts road-related crash costs for every existing
mile of roadway.

The southeastern states of Louisiana,
South Carolina, and Tennessee rank in the top 10 on both maps, earning
them the status of "worst road-related crash problems," according to
the TCC study.

By contrast, California and most of the
northeast corridor rank high in crash costs per roadway mile (see
below) and much lower in costs per million VMT (see above). The study’s
authors, who hail from the Pacific Institute of Research and Evaluation,
attribute the trend to "traffic density" — making a powerful argument
for giving special attention to expanding transit options, including
high-speed rail, in California and the northeast.

pirestudy2.jpg

Put
simply, the problem in those areas isn’t a shortage of road miles; it’s
a surplus of demand for the movement of people and goods. If anything
can be gleaned from the TCC report, it’s the importance of imposing a "fix-it-first" requirement for highways nationwide.

Still, without an alternative to driving in highly developed areas, simply repairing roads isn’t enough.

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