Since the 1950s, the majority of Americans have traveled by private automobile.  Access to cheap cars, cheap gasoline and a very extensive road network severely reduced public transportation systems in the US.  However, public transportation is starting to make a comeback.  City officials and planners have realized that a quality public transportation system does more than just get people to their destinations.  Great transit systems are part of the solution to many energy, economic, environmental and traffic challenges, and help to increase the quality of life.

In recent years, cities all across the United States have been investing in quality public transportation in order to provide alternative transportation solutions.  According to the American Public Transit Association the rate of public transportation ridership has grown by 34% – 12% more than the growth of highway travel over the same time.  Cities are eager to construct streetcars and light rail lines, Bus Rapid Transit systems and commuter rail lines to increase transportation options.  In this series on public transportation benefits, topics such as traffic, economic development, environmental impacts, and quality of life will be explored to show how public transportation can have a positive impact on those living in Central Oklahoma.


The Oklahoma City metro is one of the fastest growing metro regions in the United States.  Since 2000, the population of the Oklahoma City metro area has increased by 213,000 people and the number of work commuters has increased by over 61,000.  The Census Transportation Planning Products section of the American Community Survey found that almost 600,000 people drive to work each day in Central Oklahoma.  With Oklahoma City poised to grow even more over the coming years, more severe traffic congestion is inevitable.

When thinking about how to reduce traffic congestion, it is logical to want to add more lanes to a road.  If we increase the capacity, we should be able to decrease traffic.  However, this is not the case.  In a recently published paper, two University of Toronto professors claim that the opposite is true – that increasing road capacity actually increases traffic congestion.  This claim may seem counter intuitive, but after studying hundreds of metro areas in the United States, authors Giles Duranton and Matthew Turner, were able to make the following claim:

For interstate highways in metropolitan areas we find that VKT [vehicle kilometers traveled] increases one for one with interstate highways, confirming the “fundamental law of highway congestion” suggested by Anthony Downs (1962; 1992). We also uncover suggestive evidence that this law may extend beyond interstate highways to a broad class of major urban roads, a “fundamental law of road congestion”. These results suggest that increased provision of interstate highways and major urban roads is unlikely to relieve congestion of these roads.

Duranton and Turner say that both building more roads and adding lanes to existing roads lead to more cars on the road.  The reason for this is simple: people drive more when there are more roads to drive on.  The problem with adding more capacity to streets is that there will always be someone out there waiting to take a trip as soon as there is space on the road.   Adding capacity to high traffic roads like highways will also work to pull drivers off city streets.  Increasing transit’s role in commuting does not necessarily mean that traffic will decrease, the authors told DC Streetsblog.  “You should expect the same thing to happen if somebody gets out of their car and gets on the bus, it’s bringing up a little bit more room on the roads, and there’s somebody out there waiting to use it.”

This doesn’t suggest that building transit is useless.  Increased transit use will help stabilize increases in congestion and maximize the value of a transportation network.  With more options to choose from, commuters will spread out between the modes, increasing the efficiency of the system.  A balanced network of roads and public transportation will allow the system to work more efficiently and reduce the need for expensive investments in the future.  A quality public transportation system benefits all users of the transportation network.  Drivers will not have to worry about increased congestion and transit users will enjoy the quality of life improvements that will be explored later in this series.

The whole region will also benefit from the next topic of discussion: economic development.  Public transportation has been shown to be an effective catalyst for economic development along transit routes.  We will explore how this works and what it means for the Oklahoma City metro.

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