For many college students, having a car can end up being more of a hassle than it is a convenience. Parking is scarce and lots are far away, and the cost of insurance, gas and maintenance can add up fast.

On the other hand, relying on public transportation or walking can cause its own set of headaches, which is why a number of companies have begun to offer car sharing: cheap hourly car rental services for people who only need a car from time to time, but not often enough to merit actually owning one.

Enterprise Rent-A-Car has recently unveiled a car sharing service on the University of Massachusetts campus called WeCar, which is available to university students, faculty and staff, as well as the general public. The service allows members to reserve cars on an hourly basis, for between $8 and $9 per hour.

Enterprise hopes that students will switch to using WeCars, which are located in designated spots in the Campus Center Garage, where they are available for pick-up and drop-off. Currently, three car models are offered: the Ford Focus and Fusion, and the Nissan Cube. Members of WeCar, like ZipCar and other car-sharing services, can reserve cars online and use a card that automatically locks and unlocks the car when held up to a sensor. Gas, which is covered by the service, is paid for with a card in the glove compartment.

Membership also covers basic insurance and is available to anyone over 18 instead of 21, which is the standard minimum age requirement for car rental services.

"Most college students are under 21 and can't rent cars. WeCar aims to solve this problem," said Heena Patel, a spokesperson for the company.

Besides the added convenience, Enterprise hopes that the WeCar service will appeal to people's environmental sensibilities by encouraging less frivolous driving. The more people share the cars they drive, the fewer cars there will be on the road.

To add to this spirit of green thinking, all of the cars offered by the service are highly efficient. The Ford Fusion, which is equipped with a hybrid engine, can get up to 41 miles per gallon. "The WeCar service fits in with the university's ongoing sustainability efforts, which we are happy to support," Patel said. "It reduces congestion on streets and in campus parking lots."

WeCar operates its car-sharing services at more than 50 college campuses through the U.S. and Canada, expanding on its fleet of more than a million cars and trucks. Enterprise Rent-A-Car has an on campus site as well as a local Amherst branch just a few miles away on College Street. "With an office right on campus, we have a centralized point to maintain the vehicles, and if customers have any issues, our staff is right there on hand to take care of it right away," Patel said.

WeCar adds to the transportation options for students in the five college area, and will be competing with ZipCar's service, which is available at Amherst, Smith and Hampshire colleges.