Just two days after car rental giant Avis acquired Zipcar for $500 million, the car-sharing company has announced a new weekday driving program called the Access Plan, which is offered sans annual membership fee, and is being rolled out initially as a pilot program in Toronto and Vancouver, Canada.

Founded in 2000, Zipcar provides cars, billable by the hour or day, to its members. It claims more than 767,000 members and 10,000 cars globally, operating in the US, Canada, the UK, Spain and Austria. Zipcar offers more than 30 makes and models of self-service vehicles.

Students are a big demographic for the company too, with its University program offering a more cost-effective way of getting around than owning a car, and it opened its doors to dozens more institutions across the US back in October.

As for the new Access Plan, members can drive Zipcars and Zipvans from Monday to Friday (not including holidays), charged by the hour or day, and includes gas, insurance and limited mileage. The rates will be the same as the existing Zipcar plans – starting at $9 an hour in Toronto ($78 per day) and $8 in Vancouver ($72 per day).

“As the world’s largest car sharing network, it is natural for us to continue to evolve our service to meet a broader array of consumer needs,” explains Scott Griffith , chairman and CEO of Zipcar. “This new pilot plan is a key step in that direction. The Access Plan offers full entry to our entire network during weekdays without committing to an annual fee. This new plan also gives renewing Zipsters a new option if they are infrequent drivers but prefer to keep their membership active without an annual fee, just-in-case.”

So, this is a significant step for Zipcar, as it will open it up to many more potential users who otherwise wouldn’t want to commit to an annual membership. And it could prove particularly useful for those with very occasional vehicle needs, for example when moving house or doing a large monthly grocery shopping.

Naturally, getting subscribers to sign-up to Zipcar’s existing membership plan will be very much on its radar, and there will like be a fair bit of up-selling involved for Access Plan users.