Location-awareness makes car sharing an increasingly convenient alternative for urban dwellers looking to avoid the downside of individual car ownership. In this talk, Greg McGuire, senior engineer at Zipcar, explains how web- and location-enabled services have added a "where" dimension to the company's automated car reservation and sharing system. McGuire believes these improvements make car sharing a more scalable concept, which can help stave off congestion and pollution, and allow our love affair with the automobile to continue.

Zipcar, a short-term, on-demand car-sharing company for urbanites, has enjoyed exponential growth since it started in 2000. Falling costs and technical improvements have made location data and wireless services a key part of the company's strategy. Using their self-service website, customers can quickly identify and reserve a nearby car in the company's growing fleet on a 24/7 basis. A combination of RFID and GPRS allows the driver to unlock and operate the vehicle, with usage data seamlessly collected and passed back for billing and maintenance checks. Location-awareness through E911 also helps the company keep track of its fleet - not always an easy task, as McGuire relates in amusing stories of earlier misadventures. Interestingly, Zipcar elected to forego GPS units in their cars in order to steer clear of potential violations of customer privacy.

McGuire points out several key lessons learned from the experience of adding location awareness to Zipcar's business. For example, drawing data from multiple web services adds value, but also raises risks when particular services are unavailable. It's worth considering which functions really need to be real time, and how to handle errors. The human element must also be remembered, as McGuire notes, because customers rarely have the time or interest for reading instructions. Services must be as simple and intuitive as possible.