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How FasTrak Works

Cropped version of photo of woman placing FasTrak tag on her windshieldFor Carpoolers     |     For Solo Drivers

Step 1: Order Your Transponder

There are two types of FasTrak®​ transponders, both are free. Order yours from Bay Area FasTrak®.

The new "FasTrak Flex®​" transponder has a switch that the driver can use to indicate the number of people in the vehicle. Drivers should set their FasTrak Flex® switch position before driving.

Step 2: Set up Your Account

Visit the FasTrak®​ website to create and set up your FasTrak® account.

Step 3: Mount Your Transponder

The best place to mount your transponder is on the windshield near the rear-view mirror. You can also mount it in the lower corners of the windshield. 

Visit the Bay Area FasTrak® website for more information about mounting your transponder.

Step 4: Use the Express Lanes

Drive through toll lanes and pay the toll automatically through the FasTrak® transponder.

Tolling and FasTrak®

Tolls for solo drivers are collected electronically using FasTrak®​.

The average toll rate on SR 237 for fiscal year 2014 was $2.00. The amount of the toll for single occupant vehicles will vary based on the level of real-time traffic congestion, usually between $2.00 and $4.50 during a typical stop-and-go commute, going up as high as $8.00 during high congestion.

Carpoolers using an Express Lane need to put their FasTrak® tag in its Mylar bag to avoid being charged (The new “FasTrak Flex®” does not require a Mylar bag).

If you need a new Mylar bag, call Bay Area FasTrak® at 1-877-229-8655 and speak with a customer service agent. If your FasTrak® transponder was not in its Mylar bag and you were charged a toll while carpooling, you should contact Bay Area FasTrak® at 1-877-229-8655 and speak to a customer service representative. Outside of carpool hours, all lanes will be open to all vehicles for free.


4 people carpooling with the FasTrak transponder in the Mylar bag

If you have 2 or more people in your vehicle, or have a clean air vehicle with the proper decal, or are a motorcyclist and you take the 237 Express Lane, you need to place your traditional FasTrak®​ transponder in the Mylar bag. Without the Mylar bag, your FasTrak®​ account will be charged. With a FasTrak Flex® transponder, drivers move a switch to indicate how many occupants are in their vehicle.

If you have an incorrect charge on your FasTrak® account, please call the FasTrak Customer Service Center to dispute the charge on your FasTrak® account: 877-229-8655 [Callers outside of California should dial: 415-486-8655].

HOV ONLY Fastrack highway signSolo Drivers

During normal Express Lane operations, solo drivers can use the Express Lanes with a FasTrak® transponder. Solo drivers will be charged the posted toll amount, which varies dynamically based on the level of congestion. The minimum toll amount is $0.30, and the maximum is $8.00.

When traffic is heavy on the 237-880 interchange, the Express Lanes can go into "HOV ONLY mode". This means the lane is no longer open to solo drivers paying the toll with FasTrak®​.

During HOV ONLY mode, only vehicles with 2 or more passengers, motorcycles, and clean air vehicles with appropriate decals can use the Express Lanes. When "HOV ONLY" is posted on the toll message sign, a solo driver who enters the Express Lane can be issued an HOV lane violation citation of $491.

Solo drivers who enter the HOV/carpool/diamond lane too early, or fail to exit the Express Lanes promptly, risk being cited for a carpool violation by the California Highway Patrol (CHP).

FasTrak Flex®

FasTrak Flex® is a new FasTrak® transponder that is convenient for carpoolers on I-580 in Contra Costa County and on SR 237 in Santa Clara County. It allows drivers to move a switch to indicate how many occupants are in their vehicle. FasTrak Flex®, when used properly, will allow drivers to use the Express Lanes and be charged the appropriate toll for solo drivers, or no toll at all for carpoolers and motorcyclists.

Graphic showing how to use the FasTrak Flex transponder with one, two or three or more people