Traffic snarl: Discouraging congestion

Today, Balaker and Reed discuss how infrastructure affects transportation choices. Yesterday, they looked at expanding the L.A. subway system. On Monday, they debated how to reduce congestion. Later this week they’ll focus on transit funding, alternatives to traffic and crazy ideas to fix the traffic problem.

A one-two punch of affordable housing and rail
By Bart Reed


In all sincerity, it is foolhardy to believe that any single transportation mode can decrease congestion. Some road and freeway upgrades can relieve bottlenecks. Adding new roadway capacity, however, does not help, since the phenomenon of induced demand -- when vehicles quickly take up new capacity -- compounds the traffic problem.

Rail alone will not reduce congestion, either. However, it has been shown that it can reduce the rate of congestion growth. Cities that offer complementary rail service experience congestion growth at a slower rate than those with auto-only infrastructure.

Nevertheless, these improvements are pointless as long as residential and urban development remains spread out. Part of the congestion problem lies with a failed urban model that puts a strain on transportation infrastructure. Some believe that living in a metropolis with no center -- for which Los Angeles is often mocked -- gives residents more options to live and work elsewhere. What this has led to instead is traffic everywhere. Rail may not be able to serve so many far-flung destinations, but no mode of transportation can truly accommodate so many travel patterns. Consequently, we make inefficient use of our infrastructure and in turn create gridlock by taking too many trips here and there when it would be better to do our errands in just one trip.

Job and housing density in urban corridors can bring work, shopping and leisure destinations closer to home. Light rail is the best way to promote this planning method. For those who opt to live in a suburban or rural environment, clustering commercial destinations with transit nodes and connections via commuter rail is by far preferable to forcing everyone to drive for hours every day because their jobs are unreachable via rail.

We must also note that people don’t often choose to live in suburbs. More often, lack of affordable housing forces people to move away from employment centers. Hence, comprehensive affordable housing plans must be part of transportation projects. Rail lines create environments favorable to residents thanks to the instant availability of mobility options and their accessibility to pedestrians. This is especially helpful for our growing senior population, which has fewer mobility choices.

Some smaller solutions can also stem congestion growth. Passing the true costs of gas and parking to the consumer would discourage wasteful car use. Buses can be timed to connect with rail nodes. Signals must be synchronized so buses and cars can travel at steady speeds, saving gas. Shifting port truck traffic to rail can help stem pollution. Clearing highway accidents and helping stranded motorists promptly also help. A combination of these can increase the efficiency of existing systems. Increased availability of rail and adequate development around them can give commuters more options to avoid congestion and reduce highway demand.

Bart Reed is the executive director of The Transit Coalition, a Sylmar-based non-profit dealing with issues of transportation, mobility and land use planning.

Actually, L.A. has too few freeways
By Ted Balaker

On Monday I explained that transit usually doesn’t take enough cars off the road to quell traffic congestion, and the story’s grimmer still for an often-overlooked source of congestion—freight. Almost everything stocked in stores gets there by trucks, so Bart, your little trains won’t do much to relieve big-rig traffic.

You say rail reduces the rate of congestion’s growth, so let’s look at one of these “success” stories. In post-rail St. Louis, the increase in driving dwarfed the increase in transit ridership. Transit captured less than 1 percent of new travel, and light rail grabbed even less. In other words, rail’s impact was too tiny to affect congestion. Bart, when you say rail restrains congestion’s growth, you remind me of the kid who sends his piggy bank to DC and says he helped restrain the growth of the federal deficit.

Rail transit can actually increase congestion, by, for example, sucking up funds that could be put to better use and making motorists wait longer at red lights.

And “people don’t choose to live in suburbia”? Are you sure? Harvard’s Edward Glaeser and UCLA’s Matthew Kahn note that suburbia is “associated with significant improvements in quality of living.” And since suburbanization is a global juggernaut, it’s tough to pin suburbanization on US-style policies.

But onto road building.

To many, Los Angeles proves the futility of road building. It’s home to seemingly endless freeways and the nation’s worst traffic congestion. But look closer: L.A. has lots of roads, but it also has lots of people. In fact, among the top 50 urbanized areas, LA is second to last in pavement per person and dead last in freeway miles per capita.

Imagine if officials added lanes to the I-10. Bart, you fret about “induced demand,” in which some who used to be scared off by sluggish traffic suddenly reach for their keys. I’ll also toss in “triple convergence,” the term coined by Brookings Institution scholar Anthony Downs. Here motorists modify their time, route, and mode of travel to take advantage of less congested conditions. Pretty soon the 10 might look nearly as clogged as it was before the lanes were added.

But congestion relief brought about by expanded transit service (or most anything else) would also be vulnerable to the forces of induced demand and triple convergence. Road pricing (I’m a big fan), may be the only way to completely maintain congestion relief over time.

And Bart, folks like you who hold onto outdated views of induced demand may be inducing bad policy decisions (turns out the degree to which congestion returns has been overstated).

Even Downs declares that “the triple convergence principle does not mean that expanding a congested road’s capacity has no benefits.” For example, added capacity allows for more travel, shortens the rush-hour period, and decreases congestion on surrounding routes.

Bart, you get so much wrong, but I’ll be a “glass is 10 percent full” kind of guy, and end by highlighting some points of agreement: Beating congestion requires using many approaches, including synchronizing traffic lights, clearing accidents faster, and reforming parking.

Ted Balaker is a policy analyst at Reason Foundation and co-author of the book The Road More Traveled: Why the Congestion Crisis Matters More Than You Think and What We Can Do About It (Rowman & Littlefield 2006).

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