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Transportation Final 10-15-11 -   3.3 - Commute Trips Reduced While Driving Alone

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Transportation Final 10-15-11
1. Safety
2. Preservation
3. Mobility
4. Ferries
5. Stewardship
Action Plan

3.3 - Weekday Drive-Alone Commute Rates
How effective is the Commute Trip Reduction (CTR) program at reducing weekday drive-alone commute rates?

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Data Notes

Data Source:



WSDOT Commute Options Program Measurement of both CTR and GTECs is conducted through employee surveys. Employees at CTR sites are asked to document the commute mode choices that they made in the previous week.   For the CTR program we have surveyed between 200,000 and 300,000 employees biennially since 1992.  Baseline measurement has begun at the ten functioning GTECs; however, this data is not yet available
Measure Definition:
Target Rationale:
Link to Agency Strategic Plan: Objective 3.6: Increase vehicle occupancy and use of transportation services and commute choices.

Notes: (optional)



Data as of September 30, 2009

Moving Washington:  A component of “Moving Washington” is managing demand.  Two WSDOT programs focused on reducing drive alone trips and vehicle miles traveled are the Commute Trip Reduction (CTR) and the Growth and Transportation Efficiency Center (GTEC) programs.

Also Available
Action Plan: Yes
Extended Analysis: No

 Drill Down Measures

 Summary Analysis

Commute Trip Reduction

WSDOT partners with local governments, transit agencies, regional transportation planning organizations, employers, and others to provide commute options. CTR works primarily with larger employers and is focused on reducing commute trips.

  • Nearly 1,200 worksites, with approximately 570,000 employees who commute each day, participate in the  CTR program.
  • The proportion of employees who drove alone to CTR worksites declined 16.4% from 1993 to 2009 (from 70.9% in 1993 to 54.5% in 2009). 
  • If program participants in the Central Puget Sound Region returned to driving alone to work at the same rate today that they did when they first entered the program, the freeway and arterial system would need to accommodate 22,500 additional drive-alone vehicle trips during the morning peak commute period.  These additional vehicle trips would increase freeway and arterial system delay in the morning peak by about 12,900 hours, an increase of about 7.6 percent.
  • CTR’s target is to reduce drive alone rates at all worksites by 10 percent between 2007 and 2012.

Growth and Transportation Efficiency Centers

Established in 2006, Washington’s seven Growth and Transportation Efficiency Centers (GTEC) are located in some of its most congested, and highest trip-generating urban centers. These urban centers have limited parking, high concentrations of smaller employers, and a desire to focus on smart growth and land-use policies. GTEC represents an enhanced, locally driven, community-focused implementation of Commute Trip Reduction (CTR).

  • The significance of the GTEC program is that businesses are voluntarily implementing strategies that reduce vehicle miles travelled (VMT) and greenhouse gas (GHG) emissions by providing their employees with transportation options to improve the sustainability of their communities.  
  • All seven GTEC programs are moving at least some of their original programs elements forward with various limited funding sources. Other cities are taking notice and are beginning to declare their own interest in the program.
  • Between 2007 and 2009, CTR worksites within GTECs reduced their drive alone and VMT/employee rates 200-300 percent more than that of CTR worksites not located within GTECs.  
  • From 2007 to 2009, CTR worksites in GTECs reduced their drive alone and VMT rates by about twice as much as CTR sites not in GTECs.