Induced Demand: the Congestion Relief Conundrum

As traffic backs up, your commute to work sucks.

In transportation circles it’s called congestion and there’s only one cure: widen the road.

Or so urban planners, Caltrans and most city Public Works people have thought, but there’s a conundrum to congestion relief – widening roads doesn’t seem to make things better.

Just look to Los Angeles, decades of freeway widening have done nothing to reduce the average commute time. In Orange County, where voters rejected light rail in favor of ever-widening the 405 Fwy, driving is a nightmare.

On the face of it, widening roadways should have the desired effect; instead congestion gets worse.

We can’t keep widening roads because wider roads attract more cars. It’s like a negative biofeedback loop – for a short while after a road is widened traffic moves efficiently, but soon it’s back to crawling. Traffic statisticians would say at most you’ll enjoy 4 years benefit, but the Sepulveda Pass road widening in L.A. yielded only months of relief.

And we’re not talking an issue that’s solely related to Southern California; everywhere roads are widened, the end result is the same – more traffic and more congestion.

Will the current emphasis on widening the 101 through Montecito turn out any different?

Sooner or later we’ve got to find an alternative approach…