Traffic on the Capital Beltway Express Lanes has steadily increased since they opened last November, and the average cost to drivers is increasing, as well.

On a typical workday, about 26,294 cars travel in the lanes, according to a quarterly report released Wednesday by Transurban, the private firm that built and runs the lanes. That's about 3,000 more daily trips than the company reported during the project's first six weeks of operation late last year.

"The system's functioning great. Travelers out there are adjusting to the tolling," said Transurban spokesman Mike McGurk.

The lanes appear to be providing some traffic relief to the Capital Beltway: The Virginia Department of Transportation has tracked a 10 percent reduction in traffic on regular lanes since the Express Lanes opened, said spokeswoman Joan Morris.

The average cost for a trip on the lanes increased to $1.43 in the first quarter of 2013, up from $1.07. Tolls are calculated based on how many people are using the lanes at any given time -- so when there are more cars on the road at peak periods, drivers can expect to pay more. When the project opened in November, officials estimated the average trip would eventually cost between $5 and $6.

Since the lanes do not have toll booths, anyone who uses them is supposed to have an E-ZPass for automated payment.

Carpools with at least three people can use the lanes for free, which account for about 8 percent of all trips.

Any drivers without an E-ZPass must log on to a website to pay their toll, with an added $1.50 fee, or they will receive an invoice with an additional fee of $12.50 per trip.

The website Toll Roads News reported in January that the Express Lanes had lost nearly $12 million during their first six weeks of operation because of operating costs, depreciation and financing costs. After releasing this week's report about usage of the lanes, Transurban declined to say whether the lanes were still losing money.

Virginia will receive a portion of the lanes' revenue once they become profitable and the construction debt is paid.