Suggested Citation: Shaheen, Susan A. and Caroline J. Rodier (2004) Travel Effects of a Suburban Commuter-Carsharing Service: A Carlink Case Study. Institute of Transportation Studies, University of California, Davis, Research Report UCD-ITS-RR-04-23
Since 1998, carsharing programs (or short-term auto rentals) in the U.S. have experienced exponential membership growth. As of July 2003, 15 carsharing organizations collectively claimed 25,727 members and 784 vehicles. Given this growing demand, decision makers and transit operators are increasingly interested in understanding the potential for carsharing services to increase transit use, reduce auto ownership, and lower vehicle miles traveled. However, to date, there is only limited evidence of potential program effects in the U.S. and Europe. This paper presents the travel effects of CarLink—a commuter carsharing model with explicit links to transit and employment in a suburban environment—in the context of participant demographic and attitudinal market profiles. A variety of research methods (including focus groups, interviews, questionnaires, and travel diaries) captured the following commute travel effects from the CarLink I and II programs:
Increased commuter rail mode share by 23 percentage points in CarLink I and II;
Reduced drive-alone mode share by 44 and 23 percentage points in CarLink I and II, respectively;
Decreased average daily vehicle miles traveled by 23 miles in CarLink II and by 18 miles in CarLink I;
Increased travel time but reduced stress;
Reduced vehicle ownership by almost six percent in CarLink II; and
Reduced parking demand at participating train stations and among member businesses.
The typical CarLink I and II member was more likely to be highly educated, in an upper income bracket, and professionally employed than average Bay Area residents. CarLink I and II members also displayed sensitivity to congestion, willingness to experiment, and environmental concern. The travel results of CarLink I and II are compared to those of neighborhood carsharing models in the U.S. and Europe to suggest the importance of CarLink's explicit transit and employment connections and the value of carsharing in a suburban location.