Dear Dr. Gridlock:

Here’s my complaint about the 495 express lanes Web site: There is no single map showing the entry and exits points along the entire length, one that I could print out and keep in my glove compartment to use when I am out on the roads.

As it is, if I don’t plan way ahead and look up the exit-by-exit information on my computer before I leave home, I am just plain out of luck.

— Leo Wetzel, McLean

There’s a wealth of information on the express lanes Web site at You can see detailed depictions of how to enter and exit at the access points, how to get an E-ZPass or E-ZPass Flex, the signs drivers will see, how to pay a toll if you missed one and much more.

But sometimes, you just want to have a plain, old-fashioned map you can take with you and — when not driving — stare at so you can figure out what’s where.

Before the D.C. region’s drivers got their first experience with these high-occupancy toll lanes in November, I urged them to study up, because the new lanes are more than just four new ones in the middle of the Capital Beltway.

Now, I think I was unrealistic in expecting that many travelers would research such trips. Although there’s a wealth of information available to guide commutes, most people I ask say they just get in the car and go.

By the way, Wetzel told me that he did discover a map suitable for printing. It’s on Fairfax County’s Web site. Go to the county’s Department of Transportation page, at www.fairfaxcounty
and click on “Interstate 495 Express (HOT) Lanes Project.” You can see it by clicking on “View a map.”

Free test drive

Many travelers remain reluctant to cross the threshold if they must deal with electronic tolling. They made proposals like this:

Dear Dr. Gridlock:

With all the confusion over entrances/exits on the 495 Express Lanes, why not suggest that authorities make weekends toll-free for a couple of months as a learning exercise?

— Aarif Koreishi, Mount Airy

Transurban, the company that operates the express lanes, was initially reluctant to open the lanes for test drives but decided to make this weekend free. Until 11:59 p.m. Sunday, no tolls will be collected and no E-ZPass required.

While Maryland’s Intercounty Connector began operations with a free trial period, Transurban officials were reluctant to follow that example when they opened the lanes in November, and they had good reasons.

One was a concern about safety, given that no one had any experience with this new type of lane configuration in a very congested corridor. But there also was a business reason: Transurban isn’t simply marketing access to four new lanes. This is supposed to be a different type of travel experience. You’re paying for a reliable trip at about 55 mph, and it’s the variable toll that acts as a limiter on the congestion that could mar that experience.

But so far, we haven’t seen much of a test of this dynamic tolling system, because the lanes haven’t been very crowded. Most of the questions I get about the lanes fall into two categories:

●How could a driver make an instant cost-benefit analysis in deciding whether paying for a trip in the express lanes is better than riding free in the regular lanes?

●How does a driver get in or out of the lanes to reach a particular destination?

The free test weekend doesn’t address the first question, but it might help with the second. The express lanes project rebuilt many of the interchanges along the 14 miles between Springfield and the area north of the Dulles Toll Road in Tysons. This provides commuters with new opportunities, particularly if they are going to or coming from Tysons, but many have expressed only confusion about how to take advantage of them.

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