Dear Dr. Gridlock:

Here is a suggestion to deal with congregation at doors in the Metro: Passengers should only be allowed to enter through the center doors of cars and exit at the ends.

Stephen Meskin

Columbia

I would like to hear from others who have experience that system. I passed that reader suggestion to Metro years ago. No interest. You would think anything would be better than the free-for-all we have now.

Metro's Door Way

Dear Dr. Gridlock:

I board the Blue Line at Rosslyn in the evening, and there is often a great deal of people disembarking so they can change to the Orange Line. It takes time to let them get off, and I have heard the doors-closing chime before everyone has gotten off. I grew up in Philadelphia and took the "el" to school every day. I remember people blocking your way as you tried to get off, but never did I see the doors close before everyone had boarded.

Raymond Alwine

Woodbridge

Welcome to Metro.

'Compact' SUVs?

Dear Dr. Gridlock:

I would like to bring this parking-related issue to your attention.

Many underground garages in the area have spots clearly marked for "compact cars only." These spaces are usually between cement pillars, at bad angles and extra small.

Since when are SUVs or large pickups considered compact cars? Aren't these vehicles bought specifically for their enormous size? What are they doing in the section for compact cars only? And why must they use up 11/2 spaces to get their monstrous vehicles into these tight parking spots? Awful manners. And awful parking to boot.

Please ask them to leave space for cars that are actually compact.

Amy Wilson

Arlington

You already have. Feel free to report these oafs to the garage attendant.

An Idea to Sit On

Dear Dr. Gridlock:

Regarding the proposal to install bench seats on the Metro: I realized as I was sitting next to the bench seat that when people are sitting in them, their feet stick out into the aisle and they take up as much room as the regular seats. Where's the advantage?

John T. Bennett

Alexandria

More room for standees.

Suspend Monorail Disbelief

Dear Dr. Gridlock:

I'm surprised that the recent discussion in your column on the pros and cons of monorail systems has overlooked or neglected several significant facts about these systems.

All the debate I've seen so far assumes the monorail rides atop the rail -- as in the monorails built by Disney, Seattle, Japan and most other monorail systems. This configuration, as pointed out in the debate, makes switching among different tracks very difficult and causes big problems for rescuing people from the elevated track in case of trouble.

But there is another type of monorail, one that is suspended from an overhead track. The city of Wuppertal, Germany, has been routinely and safely operating a suspended monorail public transit system since 1901 -- 102 years and counting. If you've ever seen the 1966 film "Fahrenheit 451," you've seen the Wuppertal monorail in action. In the background of one scene in the film, you can also see how Wuppertal's suspended system solves the problem of emergency egress from on high: Each train has a stairway hinged into its bottom, which is simply let down to the ground whenever the train stops between the normal elevated stations. Another advantage of the suspended-car system is that it's much easier to incorporate switches, allowing transfer between tracks.

Perhaps both the opponents and proponents of monorail systems need to stop thinking in terms of sleek Disney-style over-track monorails and instead look with an open mind at Wuppertal's century of experience with suspended monorails.

Thomas R. Harrington

Landover

I welcome the info. I also wonder why Disney, Seattle or other systems didn't use the Wuppertal model.

Don't Hold Your Breath

Dear Dr. Gridlock:

Recently there has been much discussion about a Purple Line going east and west inside the Beltway. Years ago, Metro's Red Line was extended to Shady Grove.

When can we expect Metro to extend its lines outside the Beltway toward Upper Marlboro, Bowie or even Annapolis? That would ease the traffic on Route 50!

John Whitten

Huntingtown

I don't see it happening in our lifetime, although it would be nice. Metrorail costs a lot of money, and Maryland is struggling with a budget shortfall of $1 billion-plus.

The federal government isn't inclined to subsidize the enormous construction cost, either. The feds recently told Virginia that it would not underwrite the $4 billion cost of an extension to Dulles International Airport. Sorry.

Transportation researcher Diane Mattingly contributed to this column.

Dr. Gridlock appears Sunday in the Metro section and Thursday in Howard Extra.You can write to Dr. Gridlock, 1150 15th St. NW, Washington, D.C. 20071. He prefers to receive e-mail, at drgridlock@washpost.com, or faxes, at 703-352-3908. Please include your full name, town, county and day and evening phone numbers.