Drivers will need a FasTrak toll tag to use the new U.S. Highway 101 express lanes scheduled to open in San Mateo County at the end of 2021.

The Board of Directors of the San Mateo County Express Lanes Joint Powers Authority adopted a toll ordinance at a meeting earlier this month. The ordinance establishes toll collection and enforcement policies for the new express lanes.

Construction of new lanes began in March 2019 as part of Caltrans’ San Mateo 101 Express Lanes Project, which aims to reduce traffic and travel times and encourage carpooling.

Lanes in the first phase of the project, from the Santa Clara County line to Whipple Avenue in Redwood City, are scheduled to open at the end of 2021.

Tolls will be charged through the FasTrak system and customers will need a FasTrak Flex toll tag to use the express lanes. The Flex tag allows people to show how many passengers are in the vehicle.

Certain vehicles will be eligible to travel toll-free or for a discounted rate in the express lanes. For example, vehicles with three or more people are exempt from tolls.

Other vehicles — such as motorcycles, public transportation vehicles, emergency vehicles and California Highway Patrol vehicles — will also be exempt from paying tolls. These vehicles will still need a FasTrak toll tag.

Vehicles with two people can receive a 50 percent toll discount, along with some clean air vehicles, or CAVs, with a valid CAV decal from the Department of Motor Vehicles.

People without a FasTrak toll tag could face fines or penalties that include the cost of the toll and an additional fee in some cases.

Toll costs will be adjusted to keep traffic flowing smoothly, depending on demand and traffic patterns.

The board plans to revisit the discount before the second phase of the express lanes opens at the end of 2022. The second phase of lanes are from Whipple Avenue to Interstate 380 in South San Francisco.

More information on the San Mateo 101 Express Lanes Project is available online.