Md. Is Retooling I-495 Junctions to Clear Congestion

By Robert Thomson
Sunday, August 19, 2007

Dear Dr. Gridlock:

Can you explain the rationale behind the changing traffic pattern at University Boulevard and the Capital Beltway?

There's a new traffic signal, and traffic exiting the outer loop onto University Boulevard will now have to make a left turn at this signal to go east on University and will have to make a full right turn rather than merge into the westbound lanes. Traffic on University will have an extra signal.

This makes little sense to me, since this light in particular would seem to impede the flow of traffic with the additional consequence of adding to the area's auto emissions, forcing cars to idle where they had not been and to accelerate from a full stop.

Todd Carton


Maryland is rebuilding many of its ancient interchanges along the Beltway to reduce congestion and eliminate some dangerous merges. The projects vary, but they tend to include wider ramps and new signal lights.

Nobody likes to slow or stop. In fact, that's how the interchanges got so dangerous. Drivers entering and exiting the outer loop at University Boulevard were using the same merge lane, creating a tight weaving pattern in which they had to make quick guesses about what other drivers would do.

Police recorded 11 crashes there from 2003 to 2005, said Chuck Gischlar, a spokesman for the Maryland State Highway Administration, which is in charge of the $1.6 million construction.

The new setup took effect last week. One ramp handles all exiting traffic, and the second ramp has been closed. As drivers come up the exit ramp and approach the new traffic signal, they find two lanes for left-hand turns and two for rights. Drivers in the far right lane can make a turn on red, but those in the other right lane can't.

Although the ramp's surface was rough, the traffic pattern worked well when I drove it a few times. One thing I didn't like was insufficient warning that the second ramp, the one that used to be Exit 29B, had closed. But the highway administration has put up a message board before the exit reading "MD 193 east and west -- use exit 29," and that should help.

The light on University Boulevard will favor interstate traffic and be timed to avoid backups, Gischlar said. It wouldn't hurt traffic to go slower past the three schools on that stretch of University.

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