Friday, December 08, 2006

Debunking the myth of the double-decker Schuylkill Expressway as a panacea to any of the region's traffic woes

Yea, we heard it all before. John Perzel's been hollarin' about it for years. And now apparently Richard Geist is on board. They want to build a second level on the Schuylkill Expressway in some crazy cockamamie scheme to alleviate traffic.
KYW's Tony Romeo reports that privatization of Pennsylvania roadways like the turnpike could open the door to some much needed relief on the Schuylkill Expressway.

Governor Rendell says he wants to hear from companies who'd be interested in running the turnpike in exchange for up-front cash, and Richard Geist (R-Blair County), chairman of the state House Transportation Committee, says there are other roadways in Pennsylvania that would be candidates for similar public-private partnerships.


If legislation Geist has drafted to allow that to happen is passed, he predicts that a proposal to expand the capacity of the Schuylkill Expressway by widening it some places and building an upper deck in others would be on a fast track:


"It wouldn’t take the normal 14 years that it takes in Pennsylvania. A project like that could be up and running in three."
The problem, kids, is that you can never build enough road to alleviate peak hour traffic. More cars come as soon as the road has increased capacity. Traffic engineers (some would call them "experts") even have a name for it: triple convergence.
The least understood aspect of peak-hour traffic congestion is the principle of triple convergence […] This phenomenon occurs because traffic flows in any region's overall transportation networks form almost automatically self-adjusting relationships among different routes, times, and modes.

For example, a major commuting expressway might be so heavily congested each morning that traffic crawls for at least thirty minutes. If that expressway's capacity were doubled overnight, the next day's traffic would flow rapidly because the same number of drivers would have twice as much road space.

But soon word would spread that this particular highway was no longer congested. Drivers who had once used that road before and after the peak hour to avoid congestion would shift back into the peak period. Other drivers who had been using alternative routes would shift onto this more convenient expressway. Even some commuters who had been using the subway or trains would start driving on this road during peak periods.

Within a short time, this triple convergence onto the expanded road during peak hours would make the road as congested as it was before its expansion.

Experience shows that if a road is part of a larger transportation network within a region, peak-hour congestion cannot be eliminated for long on a congested road by expanding that road's capacity.
How enlightening. Seriously. Read it again. In fact, you might want to check out the whole report.

Take a minute and think about it. In order to significantly alleviate the region's automobile traffic congestion via greater road capacity, "Governments would have to widen all major commuting roads by demolishing millions of buildings, cutting down trees, and turning most of every metropolitan region into a giant concrete slab."

That doesn't sound too smart, does it?

Instead of spending billions on a sprawl-inducing, smog-proliferating, monster highway, why not pursue a project that would actually do a lot more to address the problem… one that would "serve communities along this corridor, revitalize the old towns and cities along the Schuylkill River, encourage smart growth and development patterns that preserve open space, and reduce traffic, air pollution, and noise pollution related to automobile use." One that would basically make the Philadelphia region a lot stronger.

What could do all that? The Schuylkill Valley Metro Commuter Rail Line, that's what. Remember her? She was a fucking knockout. A ten. But all the toolish pols were intimidated by her sexy curves and overall hotness. (And, of course, the lack of federal funds — thanks dubya.)

Regardless, if people are going to start talking about building an extremely reactionary and moronic double decker Schuylkill Expressway expansion, we’re sure as shit going to start talking about sensible transit alternatives. And they don’t get much hotter than the fricking Schuylkill Valley Metro.

Hell, another alternative that’s way better — bury the goddamn expressway. At least we’d be able to reclaim one of our riverfronts.

UPDATE: New lead photo via Philly Skyline. Old Image below.

The Schuylkill Expressway, pre double decker
Related:
Coming soon to a toll road near you — the Pennsylvania Comcastic Turnpike On Demand Information Superhighway [KYW1060]
Traffic: Why it’s getting worse and what government can do (hint: it’s not build more highways) [Brookings Institution]
Schuylkill Valley Metro — you had us at hello [Official Site]
In my country there is problem, and that problem is transport [SEPTA]
Take it to the bank — Penn students propose a way to connect their campus to the Schuylkill [Philadelphia Weekly]

3 comments:

Anonymous said...

As a compromise, how about if they build a light rail line along the length of the Schuylkill as part of any highway expansion? Perhaps the sight of a train zipping past everyone stuck in traffic will convince more drivers to use mass transit.

Anonymous said...

Another reason why any expansion of I-76's capacity is also pretty much impossible is that it would fail all environmental studies. You would never be able to build a highway today that close to a river.

Ruby Legs said...

I second the idea of a light rail line built along the length of the Schuylkyll. Put that on some sort of cockamamie elevated thingamajoobie.

Maybe then I'd actually think about going to KOP.