Colorado has three main toll roads, and each one uses a different payment system

Colorado's toll roads are the Northwest Parkway, the E-470 tollway, and I-25 Express Lanes. Each one lets you pay in a different way — some accept a transponder you mount in your car, others take a photo of your license plate and bill you later, and some let you pay cash at a booth. Which option works for you depends on which road you're using and whether you drive it regularly or just once.

If you drive the same toll road often, a transponder (a small electronic device) saves you money through discounts and means you don't have to stop or worry about a bill arriving late. If you drive a toll road rarely, paying by license plate photo or cash is simpler — you don't need to set up an account or buy equipment.

Key Takeaways

  • The Northwest Parkway, E-470, and I-25 Express Lanes each have their own payment system, so you cannot use one transponder on all three roads.
  • A transponder gives you a discount on tolls and is the fastest way through, but you pay an upfront fee to buy or lease it.
  • License plate billing (pay-by-plate) charges you automatically based on a photo of your car, with no transponder needed.
  • Cash payment is available at some toll plazas, but it costs more per trip than a transponder or pay-by-plate account.
  • You can check your toll balance, add money, or dispute a charge through each road's website or customer service phone line.

Northwest Parkway transponder and pay-by-plate options

The Northwest Parkway runs from I-25 north of Denver to I-76 near Boulder. To use it, you can buy a transponder called an E-PASS for about $25, or you can use pay-by-plate and let the road photograph your license plate and send you a bill. Tolls on the Northwest Parkway range depending on the time of day and how far you drive, but a transponder holder pays less than someone who pays by plate.

If you choose a transponder, you set up an account on the Northwest Parkway website, buy the E-PASS device, mount it on your windshield, and add money to your account. The transponder reads automatically as you pass through the toll plaza, and your account balance goes down. If you choose pay-by-plate instead, the road's camera captures your plate, and you receive an invoice by mail or email within a few days. You then pay online, by phone, or by mail.

To set up either option, visit the Northwest Parkway website or call their customer service line. You will need your vehicle's license plate number and a valid payment method (credit card or bank account).

E-470 tollway payment methods

E-470 is a 47-mile tollway that forms a partial loop around the Denver metro area, connecting I-25 south of Denver to I-76 northeast of the city. Like the Northwest Parkway, E-470 offers both a transponder and a pay-by-plate option.

The E-470 transponder is called an E-PASS, and it works the same way as the Northwest Parkway version — you buy it, mount it, and add money to your account online. Transponder users pay a lower toll rate than pay-by-plate users. If you use pay-by-plate on E-470, the road photographs your license plate and mails or emails you an invoice. You pay within a set number of days to avoid a late fee.

You can open an E-470 account and order a transponder through the E-470 website. Customer service is also available by phone if you have questions about your account or need to dispute a charge.

I-25 Express Lanes and their transponder requirement

The I-25 Express Lanes run on I-25 between downtown Denver and Castle Rock, about 40 miles south. Unlike the other two toll roads, the Express Lanes require a transponder — you cannot use pay-by-plate or cash. The transponder is called an ExpressToll tag, and you must have one to drive in the Express Lanes during peak hours (roughly 6:30 a.m. to 9:30 a.m. and 3:30 p.m. to 7 p.m. on weekdays).

During off-peak hours, the Express Lanes are free and open to all vehicles, so you do not need a transponder if you only drive them at night or on weekends. During peak hours, tolls change based on traffic — the heavier the traffic, the higher the toll. This is called congestion pricing, and it is designed to keep traffic moving.

To get an ExpressToll tag, visit the ExpressToll website or call their customer service number. You will need your vehicle's license plate and a payment method. The tag itself is free, but you must maintain a minimum balance in your account (usually around $10 to $25, depending on current policy) to drive during peak hours.

How to add money and check your balance

Each toll road lets you manage your account online or by phone. For the Northwest Parkway and E-470, you log into your account on their websites and add money using a credit card or bank account. You can set up automatic replenishment so that money is added to your account when the balance drops below a certain amount — this means you never run out of funds mid-trip.

For the I-25 Express Lanes, you manage your ExpressToll account the same way. You can check your balance, view your trip history, and add money anytime. Most accounts let you set up alerts so you know when your balance is low.

If you do not have a transponder and are using pay-by-plate, you do not need to add money in advance. Instead, you receive an invoice after each trip and pay it by the due date listed on the invoice.

Cash payment and toll plaza locations

Cash payment is available at some toll plazas on the Northwest Parkway and E-470, but not on the I-25 Express Lanes. If you pay with cash, you will pay a higher per-trip rate than transponder or pay-by-plate users. Cash booths are staffed during certain hours, so if you arrive outside those hours, you may not be able to pay in cash and will need to use a transponder or pay-by-plate instead.

Because cash payment is less convenient and more expensive, it is best used only if you drive a toll road very rarely and do not want to set up an account. For regular drivers, a transponder or pay-by-plate account saves money and time.

What to do if you receive a toll violation or dispute a charge

If you receive a notice that you owe a toll and you believe it is wrong, each toll road has a process to dispute it. You can contact the toll road's customer service by phone or through their website and explain the issue. Common disputes include being charged twice for one trip, being charged for a trip you did not make, or a transponder malfunction.

When you contact customer service, have your invoice or violation notice ready, along with details about the trip (date, time, and direction). The toll road will investigate and either reverse the charge, adjust your account, or explain why the charge is correct. This process usually takes a few weeks.

If you believe a violation notice is incorrect, you may also have the right to contest it in writing or request a hearing, depending on the toll road's rules. Check the notice itself for instructions on how to proceed.

Frequently Asked Questions

Can I use one transponder on all three Colorado toll roads?

No. Each toll road has its own transponder system — the Northwest Parkway and E-470 both use E-PASS, but they are separate accounts, and the I-25 Express Lanes use ExpressToll. If you drive all three roads regularly, you will need separate accounts and transponders for each.

What happens if I drive a toll road without a transponder or pay-by-plate account?

On the Northwest Parkway and E-470, the road will photograph your license plate and send you an invoice. On the I-25 Express Lanes, driving without a transponder during peak hours is a violation, and you will receive a notice with a fine. You should set up a pay-by-plate account or get a transponder before driving.

Do I have to use a transponder, or can I always pay by plate?

On the Northwest Parkway and E-470, you can choose either a transponder or pay-by-plate. On the I-25 Express Lanes, you must have a transponder to drive during peak hours. Pay-by-plate is not an option there.

How much does a transponder cost?

The E-PASS transponder for the Northwest Parkway and E-470 costs around $25 to purchase. The ExpressToll tag for the I-25 Express Lanes is free, but you must maintain a minimum balance in your account. Prices may change, so check each toll road's website for current costs.

Can I get a refund if I move out of Colorado or stop driving toll roads?

Most toll roads will refund your account balance if you close your account, though there may be a small processing fee. Contact customer service with your account number and request to close your account. Refunds are usually issued within a few weeks.