On the Westpark Drive bridge looking down at I-495 southbound traffic, with Express Lanes on the right side of photo. (Tracy A. Woodward/The Washington Post)

A year ago this weekend, the 495 Express Lanes debuted a new type of travel for the D.C. region.

Jennifer Aument, now U.S. business leader for Transurban, explained to reporters how the tolls would rise and fall depending on traffic conditions. Drivers would look at variable message boards to see what they’d pay for a reliable trip. There would be no toll booths. Drivers would need to get one of two types of E-ZPasses. State police would be watching for drivers claiming the carpool exemption when they had fewer than three people aboard.

Some of our expectations about the new system have held up, and some new issues emerged among drivers.

Nothing held up better than the initial notion that this was going to be the most complicated driving system most commuters had ever experienced.

Opening week was dominated by reports that some drivers were entering the lanes by mistake, and either swerving out of them or — to the horror of traffic safety officials and fellow drivers — backing up on the Capital Beltway.

Such misbehavior has diminished. When I see drivers swerving out of the lanes, it’s because they are misusing the express-lane entrance ramps as passing lanes.

When the lanes opened, drivers were very curious about whether police could identify motorists claiming the carpool exemption without the proper number of people aboard. Virginia State Police spokeswoman Corinne N. Geller said police recorded 594 violations of the carpool rule between opening day on Nov. 17, 2012, and Oct. 26.

In that same period, police reported 1,388 violations for unauthorized vehicles. (The rules ban trucks with more than two axles and vehicles with trailers in tow.)

Transurban’s latest quarterly report put the average number of weekday trips in the express lanes at 37,574.

For that entire stretch of the Beltway, including the regular lanes, police issued 698 speeding citations and 725 reckless driving citations.

While using the new system was bound to be complicated, I didn’t anticipate the extent to which the variable tolling and the new lane-access points would prove either baffling or off-putting to drivers.

Drivers continue to complain that, when they reach the points where they must pick between the free lanes and the toll lanes, they don’t have enough information about the traffic ahead to make a good choice.

This could be solved — someday — by posting travel-time signs for the express lanes and the regular lanes,

The express lanes have 11 access points, but most of them are at interchanges. Only at the ends at Springfield and the north side of Tysons Corner can Beltway drivers slip on and off. Drivers appear to have less difficulty slipping on and off than they do in navigating some of the interchange access points.

Ask me in five years whether the lanes are a success for travelers. I think the answer will be yes. By then, they will have fit into an emerging network that includes the Metro Silver Line and the 95 Express Lanes.

But I think Aument makes a fair statement when she says, “We’ve delivered on the promise we made to the region.”

Hari K. Sripathi, regional operations director for the Virginia Department of Transportation, is upbeat in his appraisal: “We are working with Transurban to improve signals, signs and pavement markings to eliminate any perceived confusion that people may still have. We have corrected some minor issues in the first week of operations and I am happy to say that we did not see any major crashes in the last year associated with the express lanes.”

Meanwhile, he said, opening up the express lanes option for nearly 40,000 daily trips benefits not only those drivers, but also the travelers in the regular lanes who have that much less competition for the free space.

Dr. Gridlock also appears Thursday in Local Living. Comments and questions are welcome and may be used in a column, along with the writer’s name and home community. Write Dr. Gridlock at The Washington Post, 1150 15th St. NW, Washington, D.C. 20071, or e-mail drgridlock@washpost.com .