January 6, 2012

Roundabout at Key Highway / Light Street

An Inner Harbor roundabout for all the wrong reasons
The real problem is that Light Street is about twice as wide as it should be. A roundabout at the end of this stretch of the Inner Harbor in front of the Science Center (upper left) would only add to its problems.

The only good thing that can be said about the city's latest proposal for a roundabout at the intersection of Key Highway and Light Street is that there is plenty of space for it. But it would be just another Inner Harbor doo-dad that ignores actual traffic conditions and long-term needs.

The proposed roundabout looks nice in the city's birds-eye sketch, shown here in the Sun, but from the street view Light Street would still be an excessive mass of concrete. 

Unlike the existing traffic circle at Harbor East, a Key/Light roundabout would not be fed by suitably scaled streets. Harbor East planners made sure that most through traffic was diverted to Fleet Street and Eastern Avenue so that the traffic circle would be a relaxed and attractive pedestrian focal point. But at Light and Key Highway, the center of the circle would be off-limits to pedestrians.

And unlike the Towson Circle, Key/Light is not a complex intersection where heavy traffic converges from five opposing directions. That is the kind of difficult situation where the intense motorist interaction inherent in a roundabout is necessary and indispensable. In contrast to Towson, the right turn from Key Highway to northbound Light Street is the only major movement other than Light Street. The total traffic volume is less than one-fifth of what the Towson Circle carries.

But most crucially, a roundabout at this location would sidestep the fundamental problem of Light Street in the Inner Harbor. Light Street is simply far too wide - about 125 feet curb-to-curb. Light Street's grotesque width is actually a detriment to orderly traffic flow. Motorists jockey for position and don't know which lane they should use. The lanes don't line up from one side of the intersection to the other. Pedestrians are lost in the shuffle. The overall width of the roadway north of the intersection could easily be reduced from 125 feet to two 11-foot lanes in each direction (44 feet total).

The city knows this. Their roundabout plan includes a very awkward taper of the southbound Light Street approach to the intersection from five lanes down to two lanes. This is the kind of precipitous necking-down that is normally used only to approach emergency construction and accident zones, with temporary orange cones, flashing lights and electronic message signs. But here it would be permanent.

The intersection's major pedestrian movement is across the Key Highway leg, and here the traffic pattern would remain basically unchanged, with the same wide sweeping curb alignment adjacent to the Science Center. The big difference is that the current green/yellow/red traffic signals would be replaced by Yield signs, creating the kind of ambiguous environment that is seldom favorable for pedestrians. Traffic would be allowed to intimidate pedestrians even more than usual. Yes, motorists should "learn" how to yield to pedestrians. People have been saying that forever. But it only happens in a pedestrian-oriented environment, and as long as the Inner Harbor is disoriented from the adjacent overscaled streets, it will not happen.

The city plan's only real nod to pedestrians is to spiff up the medians so that anyone stranded in the middle of the streets waiting for traffic will not suffer too much. Right now, there is only a small concrete island on Key Highway, and there is no median at all to the south on Light Street. Out in suburbia, a median strip may seem like an oasis, but the Inner Harbor should be able to do better.

The most well-used Key Highway crosswalk would remain about the same, except traffic would be controlled by only a Yield sign instead of the red light shown. The small median in the foreground would also be upgraded, since most pedestrians would not be able to cross the entire intersection at once. 

The wider view should be narrower streets

The real solution is that instead of a wrongheaded roundabout, Light Street should be drastically narrowed. But the city wants to avoid a real solution because it would demand that they look at the much larger stretch of Light Street adjacent to the Inner Harbor, it would require real planning, it would cost real money, and it would impinge upon their sacred Grand Prix race. Even the city's long range Inner Harbor plan shows only a modest narrowing of Light Street to get rid of the McKeldin Square, recent home of the Occupy Camp.

Of course, Light Street could easily be narrowed by half in the near term using some kind of cheap delineation that is effective but far less expensive. All the traffic in both directions could be squeezed onto one side of the existing median, with the other side used for something else. Even a parking lot would have a far more human scale than the existing monster street, and it could easily serve double-duty for a farmer's market, street fairs or whatnot. The existing northbound lanes of Light Street adjacent to the Science Center line up very nicely with the street south of the intersection toward the Federal Hill business district. The result would be a nice normal narrow three-legged signalized "T" intersection.

Even an inexpensive narrowing of Light Street would have great benefits far beyond the Key Highway intersection.   Farther north at the Conway Street crosswalk, adjacent to Harborplace and the Visitors Center, Light Street even more desperately needs to be narrowed (see top photo).

But for the city designers, a roundabout fills the bill because it looks pretty in their sketches, and it would allow them to put something memorable and symbolic in the center of the circle.

All in all, the proposed roundabout is another example of how the auto domination of the 1950-1970s era still haunts Baltimore. Light Street was originally widened to its current bloated width in the early '70s in anticipation of feeding the expressway system and to replace Calvert Street along the water with the Inner Harbor promenade. Even the proposed expressway bridge next to Federal Hill looked good to the original designers who drew the sketches. The proposed Light Street/Key Highway roundabout at the same location has the same kind of geometric appeal - until you become a pedestrian or driver trying to cross it.


  1. they should just paint the 2 left lanes southbound as left turn only lanes, the right lane as right turn only, and the other as straight only...
    i think that would solve a lot of confusion.

    oh, and rip out the unused railroad tracks, and repave the intersection.

  2. That would work, Anon !!!!! Way better than a freakin' roundabout, that's for sure. Thanks. I must admit I wasn't even thinking about pure traffic engineering solutions.

    But now that you've raised the subject, it would be easy to take your idea one step further and extend the proposed new Light Street median from the south all the way through the intersection to the north, separating the southbound through and left turn lanes. This would physically prevent any car from violating the southbound lane designations. It's feasible because the only traffic legally on southbound Light Street is through traffic. Left turns from Key Highway are illegal. Should I draw this up on Google Earth?

  3. Holy cow what is this roundabout state of mind this city is in!? Way to much traffic on those streets for a round about. Throw in a holiday weekend and the back up around that roundabout will be a nightmare of epic proportions. Roundabouts only work when drivers understand basic principles of right way for other drivers as well as pedestrians, which is lacking in this city!

  4. yeah, nightmare for pedestrians crossing there. i'd think all the yuppies in fed hill walking to work would detest it.

  5. it's going to be rel fun in the rounabout when all of the illegal truck traffic avoiding the tunnel gets stuck in there. i was "stuck" at the towson roundabout this weekend for over 10 minutes becuase of "operator error". It was ridiculous.