A safety feature is removed

2009 plan had 5-foot safety median

Median (2009)

One of the most significant of the recent changes to the design for Mass. Ave. is the elimination of a 5-foot traversable median in favor of wider travel lanes.

No median and wider lines in 2010 plan

Wide lanes (2010)

The median, which would have been flush with the pavement, was intended to make street crossing safer for pedestrians and to provide a left-turn space for westbound cars.

Here’s what Mass. Highway’s own design manual says about this design feature:

16.5.8 Medians and Crossing Islands
Traversable medians, typically built of textured or contrasting materials such as stamped concrete, bricks, pavers, or cobblestones can be effective traffic calming devices particularly where periodic segments of raised median are included, as shown in Exhibit 16-8.

These medians are flush with the travel lanes but are notably different, both in appearance and in feel to the driver. Traversable medians narrow the real and apparent width of the street, and provide deflection at end points, while still permitting unlimited driveway access across them. They can serve as left-turn lanes, and allow for passing of double-parked cars.

Further, traversable medians offer opportunities for emergency vehicles to bypass stopped traffic. At intersections, the ends of the traversable medians can extend all the way through the crosswalk, thereby providing some pedestrian refuge.

MassHighway Project Development and Design Guidebook 2006 p. 16-16

Under the most-recent proposal, the median will be removed and the three travel lanes be widened from 11 to 12 feet eastbound, and from 11 to 13 westbound. The remaining foot of width will be added to the parking lane.

Besides the loss of the median, which would have been a refuge for pedestrians crossing Mass. Ave., the newest design has several other effects.

First, the wider lanes will make the road feel “fast” and encourage speeding. These are freeway widths, greater than those of the virtual lanes on the street today.

Second, to maintain the lane widths consistently most of the proposed added sidewalk width in the business district has been eliminated. Part of the sidewalk on one block will be narrowed.

With both Mass. Highway and the Board of Selectmen on record in favor of this design, where do the engineers get off changing it?

According to Rick Azzalina, an engineer with Fay Spofford & Thorndike who is advising the Town on the redesign, the problem is with Mass. Highway itself, specifically with District 4.

At the June 22 meeting, Azzalina said there was support for the median on the planning team, and an awareness of the basis for it in the design manual. However, he said that a decision had nonetheless been made not to “expend effort to persuade” District 4 to follow its own design manual. Doing so “would not be a good use of our time,” he said.

There’s a bit more about this at yourarlington.com.

As someone who is not at all steeped in the internal politics of the state’s transportation bureaucracy, I have to say that this is nuts.

On the one hand, Mass Highway boasts that its manual is a “multiple award winning” achievement that “serves as a national model.”

On the other hand, when Arlington tries to follow that model, a district office gets to say, Naahh, we don’t think so.

Who’s in charge, please?

Update: The median is back.

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