Posts Tagged traffic

Fixing Traffic Jams

Hat tip to Barry Ritholtz for this interesting article.

Urban congestion exemplifies the larger problem of effectively coordinating individual decisions to use largely unpriced goods like roads. Drivers are adept at anticipating delays and factoring them into decisions on whether and when to hit the road. But, absent tolls, they are not compelled to factor in the delays their driving imposes on others.

One recent estimate puts the price of commuter delays alone at more than $100 billion in the United States in 2010, or nearly $750 for every commuter in the country.

The article goes on to make a point I’ve read in several places:

For instance, a recent article in The American Economic Reviewby Gilles Duranton and Matthew Turner shows that road construction in the United States typically leads to a proportionate increase in utilization, leaving congestion unchanged. Build more roads and more cars will come.

As a clever summary posted on (a fascinating platform for debates on urban transportation) waggishly puts it, “Roads cause traffic.”

As I drive around our fair valley, I see “roads causing traffic.”  But, I also see some creative ways of managing traffic – the continuous flow intersections and the diverging diamond exit from the 201 onto Bangerter.  Both of these solutions make traffic flow more smoothly but they don’t actually reduce the number of cars on the road.  Both these designs feel counterintuitive the first time you drive through them – the continuous flow intersection in particular feels unnerving as you are driving on the “wrong” side of the road for a short distance.  The diverging diamond has the same feel – you’re on the “wrong” side of the road.  However, both have greatly speeded up the flow of traffic. 

I’ve mentioned before that prior to WWII, US cities had the best public transit in the world.  My grandmother recalled taking the street car in the 1920s in Salt Lake City to and from work; she started work at the age of 13, caught the street car from her home to her job, worked until school, went to school, caught the street car back to work, worked until the evening, rode it home, did homework and started over.  As a young married woman, she took the street car from her home in the Poplar Grove neighborhood to the Deseret Creamery (where she liked to brag she was the fasted butter wrapper and packer they’d ever had!).  Public transit requires long term vision and planning; it also helps if neighborhoods are mixed use – residential and commercial so that cars are less necessary.  Regular, reliable public transit is a huge benefit to urban dwellers. 

As Salt Lake County’s population continues to grow – and the counties around us also grow – we need to get serious about traffic management.  The NYT article recommends congestion pricing – charge people who use the busiest streets – along with building transportation infrastructure to make navigating urban areas easier.

, ,


%d bloggers like this: