Benefits-cost analysis is an economic tool used to measure the relative difference between the benefits and costs of projects or investments. Public investments generating benefit-cost ratios greater than one-to-one, or more than break even, are considered justifiable.
The study’s methodology is modeled upon state-of-the-art, conservative assumptions for U.S. transit investments. It compares expanding transit with taking no action. Anticipated regional population growth will cause significantly more congestion on existing highways by 2030. The study finds that expanding the rail system will yield significant mobility benefits, resulting in time savings of between 13 million and 34 million vehicle-hours from reduced vehicle delay per year, depending on the expansion option.
The benefit-cost analysis was prepared by Parsons Brinckerhoff for Sound Transit, and included analysis of three transit expansion options: a 20-year plan developed last year that would add more than 50 miles of light rail service to the region, and two new 12-year options adding 18 to 23 miles of light rail and increasing commuter rail service.
The Sound Transit Board is weighing these options and whether to forward one for a November 2008 public vote or wait until 2010. That decision will be made in July.
Background
Benefit-cost studies universally rely on the concept that consumers will choose transit when the cost is less than or equal to the benefit. Consumer costs are considered in terms of both time and money.
Direct transit user benefits
After new transit investments are made, the cost of consumer travel falls – reflecting reduced overall travel time, reduced out-of-pocket costs, and/or new transit service in areas that did not previously have transit. As the cost of using transit declines and more people use transit, more opportunities for transit use become available, transit becomes more economically attractive, and the number of transit trips increases.
Indirect highway user benefits
A number of people shifting from cars to transit, and the resulting decline in highway congestion, together lower the overall cost for those who continue to travel by car. Benefits for drivers include improved travel time/mobility, savings in vehicle operating and parking costs, and reduction in highway accidents.
External/societal benefits
In addition to individual benefits, the region would benefit from fewer highway accidents and reduced air, noise and water pollution.
The full analysis is available at http://future.soundtransit.org/documents.aspx
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Sound Transit’s regional network of express buses, commuter rail, light rail and transit facilities connects communities in King, Pierce and Snohomish counties.