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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.

Utah

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To significantly reduce today's severe congestion and prepare for growth expected by 2030, Utah needs just over 948 new lane-miles at a total cost of $2.3 billion, in today's dollars. That's a cost of approximately $41 per resident each year. Utah ranks 30th out of 50 states and the District of Columbia in terms of most lane-miles needed and 30th in the total costs of those improvements. If the state made these improvements, it would save over 39 million hours per year that are now wasted in traffic jams.

Utah has one city that currently suffers from severe congestion, which this study identifies as those areas with Travel Time Indices of 1.18 or higher. The Salt Lake City area in the north-central part of Utah is the 30th most congested region in the United States, with a TTI of 1.28. This means that driving times during peak traffic hours are 28 percent longer than during off-peak times.

Unless major steps are taken to relieve congestion, drivers in this part of Utah can expect to see a TTI of 1.59 by 2030. For an idea of how severe that level of congestion would be, note that this projection is worse than the traffic delays experienced today in places like Atlanta, Chicago, and San Francisco. In fact, only one city�Los Angeles�currently has a TTI in excess of 1.59. But Utah can significantly reduce this congestion problem by adding about 948 new lane-miles in urban areas by 2030 at an estimated cost of $2.3 billion in today's dollars.

This investment would save an estimated 39 million hours per year that are now lost sitting in traffic, at a yearly cost of $2.40 per delay-hour saved. The annual cost to relieve severe congestion in the Salt Lake City area alone is significantly lower, at $1.46 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 51 suggests, the other cities in Utah with populations over 50,000 are currently less congested than Salt Lake City, with TTIs in the 1.04�1.05 range. However, the relative increase in delay projected over the next 25 years for these cities is between 100�200 percent, which will be sharply felt by local commuters. (The 'delay' in the travel time is the portion of the TTI over 1.0.) As points of comparison, Buffalo, Pittsburgh, and Cleveland have TTIs around 1.10. So future traffic delays for the Logan and St. George areas would be slightly lower and those in the Ogden-Layton and Provo-Orem areas higher than these three much larger cities.

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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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