I I495, north of Tyson's with the new hotlanes to the left. (Dayna Smith/FOR THE WASHINGTON POST)

Dear Dr. Gridlock:

What is the best thing to do when one finds oneself accidentally on a high-occupancy vehicle road during HOV hours? Is it okay to pull off to the side of the road and wait until the HOV period ends?

— P.K. Clayton, Springfield

Don’t do it. Just keep going. I understand the sinking feeling drivers get when realizing they have accidentally gotten into restricted lanes. The fines are pretty stiff. But unless you have a real emergency, don’t pull over and stop on the shoulders of our highways. It’s just too dangerous for yourself, other motorists, and the emergency responders who might pull over and offer assistance.

Of all our HOV routes, it’s easiest to make a mistake with the lanes on Interstate 66 inside the Capital Beltway. A solo driver could go straight into those lanes from an unrestricted roadway. In other scenarios, a driver has to move into a restricted lane or turn onto a ramp.

The new scenario many drivers are talking about involves the 495 Express Lanes, the recently opened high-occupancy toll lanes on the west side of the Beltway in Virginia. At most of the access points along the 14-mile route, drivers must make a turn onto a ramp at an interchange to reach the lanes. But at the north and south ends, Beltway drives can move from the regular lanes into the HOT lanes.

I’ve driven along this route many times since the new lanes opened in November and find it difficult to see how drivers can slide past all the warning signs and move left onto the express lanes’ ramp. It’s a form of distracted driving, but it can happen.

What I find outrageous is the idea that some drivers would back up or swerve on the Beltway when they suddenly discover that they’ve made a mistake. Just get off at the next exit. It’s not that far.

Liking the lanes

Dear Dr. Gridlock:

I was skeptical about the [495 Express Lanes] plan. I have since changed my mind. I commute from Loudoun County to Southeast Washington using the Dulles Toll Road, the Beltway and the Woodrow Wilson Bridge to and from work.

Taking the express lanes has saved me at least 30 minutes in traffic each way. It makes my commute so much easier and much less stressful. I gladly pay the extra money and breathe much easier while driving.

The only problem is people driving slowly in the left lane. In addition, there is the occasional truck that either doesn’t know or doesn’t care about the regulations. All in all, though, it seems to me that people are finally getting used to the flow. I just hope that not too many people find the lanes convenient, or they will just be another crammed traffic nightmare.

— W. Moore, Lovettsville

Two-axle trucks are okay in the express lanes. Eighteen-wheelers are not. They’ve been getting pulled over by state police.

Moore sure has a long commute. If I had to drive most of the way across the D.C. region twice daily, I’d also pay a few bucks to save time.

Yet Moore doesn’t match the profile of the typical HOT lanes user, as described by the lanes’ operator. The route from the Dulles Toll Road takes in just about all of the express lanes route.

The operator, Transurban, expects that most drivers will go just a few exits.

Also, Moore seems at peace with just getting in the express lanes and going, even though the time savings and the cost of using the lanes could vary from day to day. I think it’s a logical decision. The route goes past the congestion around Tysons, so the express lanes will almost always save time.

But I’ve heard from many drivers trying to do a more precise cost-benefit analysis when they see the toll signs, and so far, that’s proved very difficult.

Many have no idea how bad the traffic in the regular lanes will be until after they’ve made a lane commitment.

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.