Car Sharing

Such a program involves the widespread and convenient distribution of cars throughout high traffic areas in the city. Individuals then pay a monthly fee for the right to use any of the vehicles. The fee includes the price of the car itself, gasoline, insurance, maintenance and parking.[1] Participants have a card that acts as a key for the vehicles which they can then rent for any amount of time. The goal of the program is that these fleet vehicles act as a substitute for personal vehicles and reduce the total number of cars on the road, therefore theoretically reducing the amount of emissions.

Strategies and Greenhouse Gas Reduction

  • Work with Pierce Transit or other entities to bring a car-sharing program to the City. Evaluate the potential to make this an all-electric fleet as costs and technology improve.
  • Evaluate using a car sharing program in lieu of Municipal passenger vehicles.

GHG Reduction Estimates: 735 Tons CO2 assuming each car-share vehicle replaces 5 other vehicles and that 20 cars will be introduced for the city fleet and 20 will be introduced for the community.

Cost to the City
Moderately Expensive

There are varying degrees of participation on the city's part. If the city chooses to implement its own program then it will be responsible for a wide range of costs, both up front and ongoing maintenance costs. The more likely option is to encourage a private company such as Zipcar to start a car-share program within the city, mostly separate of the city itself. With this route the city is responsible mostly for recruiting the initial members which would most likely incur some cost of staff time, and then the ongoing advertising and encouragement of the program. In Arlington, VA the county has used federal Congestion Management Air Quality (CMAQ) funds to support program elements such as discounts to users, subsidies to the company itself, promotional events and so on. That support, which has helped make the car-share program viable, has cost Arlington County $85,000 over two fiscal years.1 While it is unlikely that funds have been set aside that could be easily accessed for implementing this strategy it is possible that the city could follow Arlington's example in using federal CMAQ funds.


  • General Population: Those members of the city population who trade the use of their own vehicles for the shared use of the car-share fleet vehicles and those who begin using the fleet vehicles in lieu of some other form of transportation.
  • City Employees: If the city chooses to replace part or all of its fleet with these car-share vehicles then city employees will have to adjust.


  • For the program to be cost-effective for the private company (the largest being Zipcar--recently merged with Flexcar) it requires an initial customer base of 300 signed up in advance. City staff time may need to be spent to advertise and recruit the minimum number of initial customers for the program.
  • The City will have to educate its employees on the transition from city-owned fleet vehicles to the car-share program vehicles.
  • Designated, permanent parking spots must be established in key areas for the car-share vehicles.


  • Fewer parking spots are required, allowing for other uses of the space.
  • Reduced traffic and congestion. By reducing the number of vehicles on the road through the car share program, car sharing reduces traffic and congestion throughout the city. According to, every car-share vehicle replaces 20 private vehicles and participants in the car share program drive 50 percent less.[2]


  • General population
  • City employees
  • Private car-share company

The success of some parts of this strategy should be relatively easy to track given the cooperation of the private company in recording how many users have either reduced their use of a private vehicle in exchange for the car share vehicle. Other parts, such as reduced congestion within the city would most likely be much more difficult to track over time.

If the city chooses to use a private company for the car-share program then the first step is to recruit the minimum required customer base of 300. Part of this customer base could come from the city itself through the transition of its own fleet vehicles to the private company's fleet. The recruitment process would include a comprehensive marketing and educational campaign throughout the city, starting in the areas where the fleet vehicles would initially be established. Funding would have to be acquired to provide for any discounts or other incentives the city may choose to pursue as well as for the promotion of the program. At the same time the city would have to designate specific, strategically located parking spots for the programs vehicles and would have to institutionalize their enforcement.

Success Stories
Arlington, VA
The county implemented a pilot program for car-sharing where they brought both Zipcar and Flexcar car-share companies (now merged as Zipcar) into key parts of the city. They engaged in an active advertising campaign and provided a number of financial benefits in the form of subsidies for the companies and discounts for the average consumer. As a result the city saw a wide range of improvements on a relatively small but growing scale, especially with respect to congestion. Summarized here in a news article: "Arlington County Brings Car-Sharing to the Masses with FlexCar"
Arlington Car Share Program

Irvine, CA 
The city introduced Zero Emissions Vehicles (ZEV) to a number of its employees for short distance travel to transportation hubs in the city. While not exactly a publicly available service like Zipcar, this system provides an example of how the City of Tacoma could introduce shared-use vehicles into its fleet and how they could select vehicles that are Partial Zero Emissions Vehicles (PZEV) or even Zero Emissions Vehicles (ZEV). U.S. Council of Mayors - Climate Change Best Practices Manual -- pg. 59

Saint Paul, MN
City supported Hourcar car sharing program by providing discounted parking spots for the vehicles in the program. Initial membership was 240 individuals and the program introduced twelve hybrid-electric cars (Toyota Prius model). The Hourcar program works in essentially the same way as Zipcar and other car share programs. As neighborhoods develop a "critical mass" of potential customers the program expands to that area as well. Each Hourcar vehicle is estimated to replace twenty private vehicles. U.S. Council of Mayors - Climate Change Best Practices Manual - pg. 65

Seattle, WA 
Seattle is home to Flexcar (newly merged with Zipcar) and has therefore been on the forefront of the car share landscape. In the city's Climate Action Plan it is recommended that $100,000 be used to further promote "alternatives to single-occupant vehicle travel" including "Flexcar". Clearly, it is considered an important element to reducing the number of single occupancy vehicles (SOVs) in the city. Seattle Climate Action Plan. Sept. 2006

Portland, OR 
Portland lists car sharing as an alternative to SOVs in its Climate Action Plan. The initiative consists of further promoting and educating the public about this and other alternatives to SOVs. Car sharing is already available in Portland with Flexcar (and soon to be Zipcar).  City of Portland: Local Plan on Global Warming. April 2001

[1] "Arlington County Brings Car-Sharing to the Masses with FlexCar" Arlington Car Share Program

[2] Green Benefits from Zipcar