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Congestion vs. Sprawl- The Traffic Debate Continues

The Texas Transportation Institute’s annual Urban Mobility Report is widely considered the industry standard in national traffic reports.  This year’s UMR states that the annual cost of traffic to the average commuter is roughly $713 a year.  This price is the grand total of a multitude of factors, including the price of extra gas spent idling in grid-lock, the increased price of consumer goods that need to be shipped through traffic, pay loss from missed hours at work, and many other factors.  It’s clear from the report that the traffic situation in this country, especially near major cities, it worse today than it’s ever been.  This leaves the question- how do we fix it?

That is the topic of some debate.  The TTI itself recommends that at the very core, we can solve the problem through “traditional road building and transit use.”  Many experts argue, however, that this will only exacerbate the issue.  As we saw in class, in many cases building a series of new roads will only serve to lengthen the travel times of everyone in the system.  New evidence brings about a shocking conclusion; this is not true only for a handful of carefully crafted special cases, but rather, the idea that building new roads increases traffic and congestion is the case in almost every major city in the US.

A new University of Toronto study puts forward the aptly named “fundamental law of highway congestion.”  Simply, this states that, in sufficiently populated areas (like the ones where traffic congestion is at its peak), there are vastly more drivers than roads.  Thus, any new road built will instantly be filled to capacity, doing little to stave off congestion or shorten commutes.  This is very similar to the law of “peak hour” congestion put forward by road researcher Anthony Downs in 1962, which states that at peak hours of any heavily populated area, every road will be filled to capacity, regardless of how high that capacity is.  This takes our in-class example from special case to the norm, showing that more often or not, building a new road will either do nothing or actually lengthen average commutes.

So what then are the solutions?  A CEO for Cities report titled “Driven Apart” suggestions that the answer lies not in highway construction but urban planning.  The report suggests that the traditional method TTI uses to rank the nation’s worst traffic cities, time spent driving with no traffic divided by time spent in congestion, is inherently misleading.  The claim is that the issue is total time spent commuting, not the relative time spent driving in traffic verses moving at speed.  After all, isn’t a 20 minute commute through bumper to bumper traffic still better than a 2 hour commute on open roads?  While TTI would say no, many experts feel as though the industry standard of comparing time spent moving freely verses in traffic is outdated and misleading when it comes to solving the real issues at hand.

Taking the claim from Driven Apart further, it is easy to suggest that the true solution isn’t to worry about reducing congestion at all.  After all, if building more roads won’t shorten commutes, aren’t we fighting a losing battle?  Instead, Driven Apart advocates for less “sprawl,” or, reducing on average the total distances that commuters need to travel.  This way, congestion or not, people are spending less time total on the road.  Of course, this is not a simple fix either; reducing the sprawl of major urban areas would require extensive changes to our urban and suburban systems, as it requires both a higher percentage of the population living in or close to the city, as well as finding ways to entice those who live further from any given city (who would have the longest travel distances) to travel elsewhere for their business and leisure.

Obviously the solution to the traffic problem isn’t simple, or else there wouldn’t be a problem at all.  However it is clear that any potential solution that could arise would have many of the fundamental ideas taught in the class at its core.


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