Test drives will start on the Beltway express lanes this week.

Transurban-Fluor, the private company building the lanes, will begin testing the tolling and traffic management systems as it prepares for an expected December opening. The lanes promise a faster ride on Interstate 495 in Virginia for carpoolers and those willing to pay a toll in exchange for convenience. The tolls will vary based on how much traffic is in the lanes.

"The all-electronic facility will use technology to manage travel on the Express Lanes and get drivers moving on the Beltway," said Tim Steinhilber, Transurban-Fluor's general manager for the project. "This testing phase is critical to ensure that our systems are ready to deliver faster and more predictable travel to drivers."

Officials are warning other drivers on the Beltway not to follow the test cars onto the express lanes, which will remain closed to general traffic during testing.