January 1, 2013, 1:09 amGetaround Car Sharing service started in Portland last January. There are already 450 cars in the network. This is different from Zip car or other car sharing services because the cars rented are personal vehicles. People in the network, both renters and rentees, are being asked to participate in a study on driving behaviors. The goal of the study is to find out if people change their driving habits by using a car sharing service. For example, do rentees use the bus or ride a bike more because they are renting out their car? If people are renting cars, will it change car buying habits? Does car sharing ease congestion?