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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.

Delaware

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To significantly reduce today's severe congestion and prepare for growth expected by 2030, Delaware (outside of the Wilmington area) needs almost 42.2 new lane-miles at a total cost of $56 million, in today's dollars. That's a cost of approximately $24 per resident each year. Delaware ranks 49th out of 50 states and the District of Columbia in terms of most lane-miles needed and 50th in the total costs of those improvements. If the state made these improvements, it would save almost 293 thousand hours per year that are now wasted in traffic jams.

It should be noted that this total does not included the heavily urbanized northern portion of the state which falls in the Philadelphia metropolitan area. This region, which includes the Delaware city of Wilmington and its environs, is the 25th most congested urbanized area in the United States, with a Travel Time Index (TTI) is 1.32. This means that driving times during peak traffic hours are 32 percent longer than during off-peak times. And unless major steps are taken to relieve congestion, drivers in the Wilmington area can expect to see a TTI of 1.61 by 2030, meaning they will experience travel delays worse than any present-day city in the United States with the exce! ption of Los Angeles, which has a TTI of 1.75.

Philadelphia-Wilmington could significantly reduce congestion by adding about 1,900 new lane-miles by 2030 at an estimated cost of $19.6 billion in today's dollars. This includes the costs of adding 5 percent of the new capacity by building elevated roadways and tunnels, which will be necessary in a densely settled location like Philadelphia.

This investment would save an estimated 209 million hours per year that are now lost sitting in Philadelphia-Wilmington traffic, at a cost of $3.75 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.

As Table 13 suggests, Delaware really does not have a significant traffic congestion problem in other areas around the state, although there are likely to be specific sites where traffic does have some major adverse impacts. The only other city in Delaware with a population over 50,000, Dover, has a Travel Time Index (TTI) of 1.04. This means that driving times during peak traffic are 4 percent longer than during off-peak times. While this TTI does not reach the 1.18 level that this study identifies as severe congestion, the relative increase in delay projected over the next 25 years is 100 percent, which will be sharply noticed by local commuters. (The 'delay' in the travel time is that portion of the TTI over 1.0.) To put things into perspective, TTIs of around 1.08, reflect current traffic in! cities such as Cleveland, Richmond-Petersburg, and Spokane. Delaware could solve this limited problem by adding just 42.2 new lane-miles by 2030 at an estimated cost of $56 million in today's dollars. This investment would save an estimated 293 thousand hours per year that are now lost sitting in traffic, at a yearly cost of $7.64 per delay-hour saved.

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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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