Zipcar Inc. has launched its service at Chicago's O'Hare International and Midway International airports, bringing the total number of Zipcar-service airports to 26.

To celebrate this milestone, Zipcar will offer special pricing – $99 for a two-day reservation – at participating airport locations until Dec. 21, says the company.

"Since many of our Zipsters think about our service only where they live and work, this promotion is designed to remind them Zipcar convenience is available when they travel," said Zipcar President Mark Norman. "We're committed to bringing our 'wheels when you want them' service to wherever our members want to be."

Zipcar provides several rental vehicles, including Toyota Prius, Ford Escape and BMW 3-series models, within the Avis Car Rental facility at the airport. Other Zipcar airport locations include Atlanta, Austin, Boston, Denver, Las Vegas, Los Angeles, New York (JFK and LaGuardia), Philadelphia, Phoenix and San Francisco.

According to Zipcar, it plans to add additional airports before the end of the calendar year.

To make a reservation and for more information on Zipcar's airport locations, visit www.zipcar.com/airports.