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Frequently Asked Questions

What are the I-15 Express Lanes?

The award-winning I-15 Express Lanes system is the nation’s most advanced and innovative highway. It provides a flexible, four-lane “expressway within a freeway” that can be managed by expanding or contracting based on traffic flow. Brought to you by SANDAG and Caltrans, the I-15 Express Lanes are designed to offer multiple choices for commuters and were created to provide carpools, vanpools, zero-emission vehicles with an approved Clean Air Vehicle Sticker issued by the California DMV, motorcycles, MTS Rapid transit routes, and FasTrak customers with a smoother, quicker, and more reliable trip along the busy I-15 corridor. The Express Lanes also help ease demand on the general purpose lanes, benefiting all commuters and contributing to a “greener” community as commuters realize both the environmental and economic benefits of ridesharing and public transit. The Express Lanes total 20 miles of congestion-free travel from SR 163 to SR 78, and are open 24 hours a day, 7 days a week. A movable barrier separates the northbound and southbound Express Lanes, allowing operators to expand or contract the number of lanes to manage congestion and handle major incidents, special events, and related traffic management needs. The new design provides maximum flexibility to meet both the region’s current needs and to accommodate future growth and capacity.

How do I use the Express Lanes?

Carpools, vanpools, motorcycles, and zero-emission vehicles with an approved Clean Air Vehicle Sticker issued by the California DMV can use the Express Lanes for free. Solo drivers with a valid FasTrak account and transponder pay a toll to use the lanes. The I-15 Express Lanes provide maximum flexibility and quickly take users where they need to go. The Express Lanes offer more than 20 access points to and from the general purpose lanes in each direction as well as five direct access ramps from transit stations. Electronic tolling signs provide information on FasTrak toll rates as well as the estimated length of time it will take to get to various locations. There are also smaller signs along the Express Lanes that let users know when they should exit the Express Lanes in order to get to their desired destination.

How much does it cost to travel on the Express Lanes?

Carpools, vanpools, transit riders, motorcycles, and zero-emission vehicles with an approved Clean Air Vehicle Sticker issued by the California DMV may travel on the Express Lanes for free—no preregistration or transponder is required, just enter the lanes and go!

For solo drivers with a prepaid FasTrak account, a distance-based dynamic pricing system is used. The toll is based congestion at the time the lanes are entered and the total distance traveled. Every three minutes, the system recalculates the per-mile toll rate based on the level of traffic in the Express Lanes, ensuring traffic flows freely. The toll rate you see on the signs located just before each entrance to the Express Lanes shows the minimum toll you will pay if you enter the facility, as well as the maximum toll should you choose to travel to the end of the Express Lanes. The signs also advise you of one or more possible fares for shorter trips to upcoming freeway interchanges, such as SR 56.

Are there tollbooths on the Express Lanes?

No. The FasTrak toll collection system on the Express Lanes is entirely electronic. There are no tollbooths or traffic gates and no slowing or stopping to pay a toll. Solo drivers who want to use the Express Lanes must first open a prepaid FasTrak account and mount a small FasTrak transponder on the inside of their windshield. The electronic system reads the transponder each time the customer chooses to use the Express Lanes and automatically deducts the correct toll from the customer’s prepaid FasTrak account.

What times are the I-15 Express Lanes open?

The I-15 Express Lanes are open 24 hours a day, 7 days a week in both directions.

I saw a sign on the Express Lanes that said “HOV ONLY” instead of a toll rate. What should a FasTrak driver do if they see this?

If you are a FasTrak customer driving alone and you see the message “HOV ONLY” displayed on the overhead electronic toll message signs, do not enter the Express Lanes. That message is only displayed when traffic in the Express Lanes is congested and no excess capacity is available for solo drivers. If you are in the Express Lanes when the message appears, you are allowed to stay in the lanes at the rate that was posted when you entered—you do not need to exit the lanes. If you enter after the “HOV ONLY” message is displayed on the electronic signs on the Express Lanes or at the transit stations, you will be assessed a fine equal to the maximum toll and you will be charged the maximum fare, currently $8.

The Express Lanes’ electronic toll signs display travel times to the next interchange. What does that mean?

The travel times displayed on electronic toll signs are for the Express Lanes travel times. Customers asked for this type of information to ensure they are receiving value in return for paying the toll to use those lanes. Travel times for the general purpose lanes are displayed on other message signs in the I-15 corridor.

Can large trucks use the I-15 Express Lanes?

Only light trucks and sport-utility vehicles are allowed on the Express Lanes. Under California law, commercial trucks with more than two axles are not allowed on the Express Lanes.

Can I tow my trailer or boat on the I-15 Express Lanes?

No. Trailers and boats are not allowed on the Express Lanes.

Can I drive my hybrid or zero-emission vehicle on the I-15 Express Lanes for free?

Only zero-emission vehicles displaying the approved Clean Air Vehicle Sticker issued by the California DMV are allowed to travel in the Express Lanes for free with a solo driver. If you drive a hybrid vehicle, the only way to ride in the Express Lanes for free is if there are two or more people in your vehicle. The California Department of Motor Vehicles Hybrid Clean Air Vehicle Decal Program ended July 1, 2011. Owners of hybrid clean air vehicles displaying yellow Clean Air Vehicle (CAV) decals are no longer allowed to operate their vehicle in a high-occupancy vehicle (HOV) lane unless the minimum passenger requirements are met. After July 1, 2011, use of an HOV lane without the minimum required passengers may subject the driver to a citation.

What is that large work vehicle moving the barrier on the Express Lanes?

That is the Barrier Transfer Machine (BTM). The BTM is used to reconfigure the Express Lanes from two lanes in each direction to three lanes in one direction and one lane in another direction to manage traffic flow during peak traffic hours. Current traffic volumes have not triggered the need to use the BTM on a daily basis. Caltrans moves the barrier on an as-needed basis to maintain its operability, as well as when there are incidents or emergencies. While the BTM is designed for using during normal traffic flows, you may notice small traffic impacts when it is operating. Additionally, you may also notice messages on the electronic signs that will alert you to be on the lookout when the BTM is in use.

How does Rapid work on the I-15 Express Lanes?

MTS currently operates four Rapid routes that use the I-15 Express Lanes to transport riders from North County locations to their destinations in Downtown San Diego, Sorrento Mesa, and UTC. Rapid 235 and Rapid Express 280 and 290 began service between Escondido and Downtown San Diego in June 2014, and Rapid 237 began service between Rancho Bernardo and UC San Diego in October 2014. These routes feature comfortable new vehicles, frequent and reliable service, and improved station amenities. Visit to learn more about these services.

Transit stations and Park & Ride lots are located along I-15 and are connected to the Express Lanes via Direct Access Ramps (DARs). These DARs allow Rapid and other Express Lanes users to bypass general lanes and enter directly onto the Express Lanes. Rapid and other transit riders, carpoolers, and vanpoolers can take advantage of parking at the transit stations at Sabre Springs/Peñasquitos and Rancho Bernardo. Parking at the Del Lago and Miramar College transit stations are reserved for transit riders, while carpool/vanpool parking is available at nearby shopping centers.

Visit for more details.

What was the reason for constructing the I-15 Express Lanes?

The average daily traffic on I-15 ranges from 170,000 to 295,000 vehicles, with daily commute delays ranging from 30 to 45 minutes in the general purpose lanes. By 2020, traffic is expected to increase to almost 380,000 vehicles per day. Delays were expected to be as long as 90 minutes if improvements were not made. The I-15 FasTrak program successfully demonstrates that value pricing can be an effective tool for increasing the use of an HOV facility while maintaining free-flow conditions in the facility. SANDAG is committed to delivering on the TransNet promise and improving the quality of life for San Diegans. The I-15 Express Lanes system is the nation’s most advanced and innovative highway, providing a smarter way to commute as well as saving time, gas, and helping the environment.

What is SANDAG?

SANDAG (San Diego Association of Governments) is the San Diego region’s primary public planning, transportation, and research agency, providing the public forum for regional policy decisions about growth, transportation planning and construction, environmental management, housing, open space, energy, public safety, and national topics. SANDAG is governed by a Board of Directors composed of mayors, council members, and county supervisors from each of the region’s 19 local governments. Supplementing these voting members are advisory representatives from Imperial County, the U.S. Department of Defense, Caltrans, San Diego Unified Port District, Metropolitan Transit System, North County Transit District, San Diego County Water Authority, Southern California Tribal Chairmen’s Association, and Mexico. The Board of Directors is assisted by a professional staff of planners, engineers, and research specialists. More information is available on

How does the FasTrak electronic toll collection system work?

A FasTrak transponder is a small radio device that is mounted inside the vehicle on the windshield. It identifies the customer's prepaid toll account. Overhead antennas in the I-15 Express Lanes and South Bay Expressway read the transponder and deduct the correct toll electronically from the customer's prepaid FasTrak account.

Where is the toll rate posted?

I-15 Express Lanes: Electronic signs show the minimum and maximum tolls a driver can pay. Tolls on the I-15 Express Lanes are variable and change as the traffic does. These signs are located in advance of every I-15 Express Lanes entrance and at the transit stations along the corridor. For more information on I-15 Express Lanes tolls click here.

South Bay Expressway: South Bay Expressway toll rates can be found on signs at toll booths at entrances/exits along the facility. Learn more about South Bay Expressway tolls. FasTrak customers save up to 80 percent off toll rates compared to customers who pay with cash/credit at toll booths.

How do I install the transponder on my vehicle?

A transponder should be mounted inside the car squarely on the top-middle section of the windshield directly behind the rearview mirror. It should be no more than one inch from the windshield’s top edge, below any dark shaded tint. If your vehicle does not permit the placement of the transponder in that location, mount the transponder in the lower left or right corner of the windshield no more than one inch from the lower and outer edges. According to Article 13, Section 23302 of the Vehicle Code, you are responsible for mounting your transponder properly. Please note that if mounted incorrectly, the transponder may not work and you could be subject to citation.

Learn about new transponder technology

California toll agencies have begun the statewide distribution of new transponder technology through the use of stickers. Toll operators throughout the state are working together to align how this new technology is rolled out for the benefit of our FasTrak shared customers.

SANDAG is working diligently on both roadway and customer website improvements that are anticipated to roll out next year, including the introduction of sticker transponders. In the meantime, your existing transponder will continue to provide access to California’s tolled roads, lanes, and bridges. We will contact all SANDAG FasTrak customers with instructions on how and when to replace your existing transponder(s).

If you have a FasTrak account with a partner agency that has already distributed a sticker transponder and you plan to use the I-15 Express Lanes, work with your Customer Service team to be sure you have the most appropriate device for your use. Drivers with a sticker transponder will always be charged the full toll on the I-15 Express Lanes, regardless of occupancy. This means that driving in the I-15 Express Lanes with a sticker transponder will be read as single occupancy, even if you are driving as an HOV (two or more people). Removal of the stickers will break the internal antennae so they cannot be shared between vehicles; stickers can only be mounted once.

FasTrak Flex or switchable transponders should be used by drivers who would like to toggle between single-occupancy travel and 2+ or 3+ carpool lanes and be tolled accurately. SANDAG FasTrak customers currently use a mylar bag to prevent their transponder from being read while carpooling. Visit your agencies’ website for more information or for more detailed information about all the types of transponders and how they work.

If I carpool how do I avoid getting charged a toll?

I-15 Express Lanes: If you rideshare with two or more people in your car while driving on the I-15 Express Lanes, please remove the transponder from your windshield and place it in the Mylar bag that was provided with your transponder. Additional Mylar bags are available free of charge by contacting the Customer Service Center. This will prevent your transponder from being read by the FasTrak tolling system and will ensure you aren't charged the toll.

South Bay Expressway: All drivers must pay to drive the South Bay Expressway. There are no carpool discounts.

Can my FasTrak transponder be moved between vehicles?

Yes. You must provide us with the license plate number, state, make, and model of all vehicles using the FasTrak transponder. If your primary vehicle changes, you must update your vehicle information. Visit, or call 511 and say “FasTrak” to talk to a Customer Service Representative. We recommend that you sign up for a FasTrak transponder for each vehicle that you drive on a regular basis.

What happens if my transponder is lost or stolen?

Please notify us immediately if your transponder is lost or stolen. Your only liability is your transponder cost of $35 and any tolls charged to your account prior to notification. Call 511 and say “FasTrak.”

How long does the battery last?

The warranty for the battery is five years. Several factors, including prolonged direct exposure to the sun, can affect the life of the transponder. The fastest way for you to obtain a new transponder if your battery dies is to call the Customer Service Center. Call 511 and say “FasTrak” to speak to a Customer Service Representative.

Does it work for all carpool lanes or just FasTrak lanes?

Your transponder allows you to pay for the use of the I-15 Express Lanes or any other toll roads and bridges in California that use the FasTrak system. In San Diego County, the only other FasTrak toll road currently is the South Bay Expressway. Your FasTrak transponder does not give you access to any other type of carpool lane.

Will FasTrak work on freeway on-ramps?

No. Your transponder only allows you to pay for the use of the Express Lanes. Your FasTrak transponder does not give you access to any other type of carpool lane.

Does FasTrak work out of state?

No, but it does work on any FasTrak toll road or bridge in California.

My transponder isn’t beeping. Is it not working?

Your transponder will not beep on the I-15 Express Lanes. If there is a problem with your transponder, the Customer Service Center will typically notify you. If you think there might be a problem with your transponder, contact the Customer Service Center.

Can I change the battery in my transponder?

No. If you open the transponder for any reason, you will void the warranty and you will be charged $35 for the value of the transponder.

How will I be billed?

You must maintain a prepaid account with a minimum of a $10 balance and a credit card on file. The account will be automatically replenished in the amount of $40 per account, or $20 per transponder for accounts with two or more transponders, each time it goes down to $10. Monthly account and transponder fees will be deducted automatically from your account balance following the end of the month (where applicable).

What are the fees?

Will I receive statements?

With the online account management system, you will be given options for when you would like to have your monthly statement emailed to you. You also can view monthly statements online at any time. If you don’t use the online account management system, you will continue to receive an email statement each month. Quarterly printed statements are also available by request. There is a $2 cost per printed statement charged to your account. To register online, make sure the Customer Service Center has your email address on file and then visit