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Mobility Project

Traffic Congestion in America's Cities

How bad will traffic congestion be in 2030? How much construction and how many new lane miles will each state and major city need to add over the next 25 years to prevent severe congestion? And how much will it all cost? The Reason Foundation study Building Roads to Reduce Traffic Congestion in America's Cities: How Much and at What Cost? and its addendum, A Detailed State-by-State Analysis of Future Congestion and Capacity Needs, provide in-depth answers to these questions. An interactive map ranking the states by congestion and costs to reduce traffic is here and a map of the most congested cities is here.

Illinois

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To significantly reduce today's severe congestion and prepare for growth expected by 2030, Illinois needs just over 4,450 new lane-miles at a total cost of $55 billion, in today's dollars. That's a cost of $218 per resident each year. Illinois ranks 7th out of 50 states and the District of Columbia in terms of most lane-miles needed and 2nd in the total cost of those improvements. If the state made these improvements, it would save 617 million hours per year that are now wasted in traffic jams.

Illinois is home to the second most congested city in the United States, Chicago, where the Travel Time Index (TTI) is 1.57. This means that driving times during peak traffic are 57 percent longer than during off-peak times. The only drivers who experience worse traffic are those in Los Angeles, where the TTI is now about 1.75.

However, unless major steps are taken to relieve congestion, drivers in the Windy City can expect to see a TTI of 1.88 by 2030, meaning they will experience travel delays worse than present-day Los Angeles.

Chicago could significantly reduce congestion by adding about 3,800 new lane-miles by 2030 at an estimated cost of $53.9 billion in today's dollars. This includes the costs of adding 15 percent of the new capacity by building elevated roadways and tunnels, which will be necessary in a densely settled location like Chicago.

This investment would save an estimated 613 million hours per year that are now lost sitting in Chicago traffic, at a cost of $3.52 per delay-hour saved. This does not account for the additional benefits not quantified in this study, including: lower fuel use, reduced accident rates and vehicle operating costs, lower shipping costs and truck travel time reductions, greater freight reliability, and a number of benefits associated with greater community accessibility, including an expanded labor pool for employers and new job choices for workers.

While $53.9 billion may sound like an unattainably large investment, it is about 88 percent of the amount that the Chicago area's Metropolitan Planning Organization (MPO) already plans to spend in their long-range transportation plan. The Chicago Area Transportation Study Policy Committee (the region's MPO) plans to spend approximately $61 billion during the next 25 years�$33.5 billion on highway improvements and $27.5 billion on mass transit. While 12.5 percent of Chicago commuters now use mass transit, transit spending constitutes 45 percent of the region's total transportation dollars.

As Table 19 shows, Illinois' other urban areas are substantially less congested than Chicago. However, the increase in delay projected over the next 25 years for these cities is actually higher than that for Chicago. (The 'delay' in the travel time is the portion of the TTI over 1.0.) In Chicago, the expected increase in traffic delay from 2003 to 2030 is 54 percent. However, all other smaller urban area in Illinois listed in Table 19 can expect an increase in delay of between 75�133 percent, which will be sharply felt by local commuters. With projected TTIs of 1.08�1.10, cities like Decatur, Springfield, and Peoria are facing future traffic delays similar to those currently experienced in the much larger cities of Dayton, Cleveland, and Pittsburgh, respectively.

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» Return to Index Page: Study, State-By-State Data, Maps
» Return to Interactive Map of Traffic U.S. Congestion Statistics and Construction Needs

This information is excerpted from A Detailed State-by-State Analysis of Future Congestion and Capacity Needs and Building Roads to Reduce Traffic Congestion in America's Cities: How Much and at What Cost?

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