New study points to public transportation as a key weapon in combating greenhouse gases, climate change

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WASHINGTON, DC—Seattle Mayor and Sound Transit Boardmember Greg Nickels joined members of Congress and the President of the American Public Transportation Association today to announce the release of a new study on greenhouse gas emissions that lists public transportation as a key weapon in combating pollution and global climate change.

"Cars are the largest source of climate-warming pollution in the United States today,” said Mayor Nickels, “The only way to reduce our dependence on cars is to increase alternatives such as transit." 

The study found that taking public transportation can be more than ten times as effective in reducing a household’s carbon dioxide emissions than other household actions. One commuter who normally drives alone can reduce their carbon footprint by 10 percent by simply switching to public transportation. If one person in a two-car household gives up using the second car entirely, he or she can reduce the household’s carbon footprint by 30 percent. Science Applications International Corporation prepared the study, titled Public Transportation’s Contribution to U.S. Greenhouse Gas Reduction, for The American Public Transportation Association (APTA).  

"Every day, Sound Transit's network of buses, trains and light rail takes thousands of cars off the road in our region by providing more than 48,000 riders with a safe, convenient way to get where they want to go," said Sound Transit Board Chairman and Pierce County Executive John Ladenburg. “Sound Transit continues to grow and work hard to give people in our region more commute choices, making the environmentally friendly choice of transit even easier.”

Sound Transit operates a regional network of buses, commuter rail, and light rail systems that serve some of the most congested corridors in King, Pierce, and Snohomish counties. The ST Express bus network has 19 bus routes covering the three-county region, and the Sounder commuter trains provide service along with 74 miles of track between Everett and Tacoma. Tacoma Link’s 1.6 mile light rail system currently in operation will be joined by about 16 miles of light rail service from SeaTac Airport to downtown Seattle in 2009 and is projected to carry 45,200 daily by 2020. An additional 3.15-mile extension from downtown Seattle to the University of Washington is slated to break ground next year and open in 2016, adding a projected 70,000 daily riders to the system, for a total of 114,000 daily riders on the Link system by 2030.

Since beginning bus service in 1999, Sound Transit’s ridership has steadily grown, including a system-wide 11 percent ridership growth between 2006 and 2007. Sound Transit expects to have 12.8 million rail and bus riders board the system in 2007.

If approved in November, the Roads and Transit package would build more than 50 miles of light rail extensions north to Lynnwood, east to Bellevue and Redmond, and south from SeaTac Airport to Tacoma, as well as improve commuter rail facilities and expand express bus service. These investments would expand Sound Transit’s daily ridership to more than 350,000 by 2030. The transportation sector contributes of 50 percent of the regional carbon footprint, significantly more than the national average, and this proposed expansion of the region’s public transportation network has the potential to reduce vehicle miles traveled in the region by 330 million by 2030, making a significant contribution to reducing greenhouse gas emissions. For more information on the Sound Transit 2 plan, click here>>> 

Sound Transit is committed to protecting the environment and reducing the greenhouse gas emissions in its current operations as well. Public transportation produces 95 percent less carbon monoxide (Co), 90 percent less in volatile organic compounds (VOCs) and about half as much carbon dioxide (CO2) and nitrogen oxide (NOx) per passenger mile, as private vehicles. Sound Transit takes environmental protection a step further with 22 electric hybrid buses in Sound Transit’s fleet, along with an all-electric light rail system and ultra-low-sulfur fuel used in the Sounder locomotive fleet. 

In light of the new study, APTA is calling on Congress to incorporate public transportation into a national climate change strategy that includes providing additional funding levels for more public transportation investment. Specific policy goals include providing tax credits to major employers who spend resources to support mass transit ridership programs, and tax credits to developers for mixed development residential, commercial and transportation sites that encourage greater use of public transportation.

“The results of this study are astounding,” said Nickels. “With a single action, a single choice, people can significantly reduce harmful greenhouse gases by switching to public transportation for their commute.”

For additional information about the APTA study or the press conference held today in Washington, DC, go to


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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.