Starts & Stops

New traffic guide means more innovative design

MassDOT’s decision to allow city planners to use a  new traffic manual will lead to more separated bike lanes.
Lane Turner/Globe Staff file December 2013
MassDOT’s decision to allow city planners to use a new traffic manual will lead to more separated bike lanes.

It was perhaps the most boring subject line to a press release ever: “Massachusetts Becomes Second State DOT to Officially Endorse NACTO Urban Street Design Guide.”

The National Association of City Transportation Officials had recently issued a new edition of its manual on street design and road features, and Massachusetts’ state transportation secretary Richard A. Davey had officially given the OK for the state’s city planners to use it.



But what appears at first glance like public-works-engineering gobbledygook could have some important implications for Massachusetts.

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It turns out that when city and state engineers want to improve an intersection, repaint the markings on a road, or perform an overhaul on a stretch of street, they don’t just sit down at the drawing board and come up with a design from scratch. They use a traffic manual — a menu of options of pre-approved and vetted traffic markings, signals, signs, and configurations.

The manual they decide to use depends on their taste, as well as willingness to dip their toes into new and innovative waters — a prospect that can make some engineers, naturally wary of safety and liability risks, more comfortable with traditional street options.

There’s the Manual on Uniform Traffic Control Devices, put out by the Federal Highway Administration — for comparison’s sake, it’s like Johnny Carson, a little old, a little staid and kind of conservative, but catering to the broadest possible audience with relatively tried-and-true material.

Then there’s the American Association of State Highway and Transportation Officials’ manual — a little fresher, like David Letterman, but cautious not to offend.


And finally, you’ve got NACTO — cutting-edge, unconventional, and willing to go out on a limb. It’s the Jon Stewart of traffic manuals.

So what does it mean for cities in Massachusetts that the state has agreed to incorporate the more edgy manual into its arsenal?

Most immediately: more separated bike lanes, traffic calming measures like speed tables, intersections with curb extensions for pedestrian visibility, bicycle-specific traffic lights, and the oh-so-beloved parklets (parking spaces turned into miniature urban refuges).

“It lays out in clear language the principles that go into building a sustainable, multi-modal urban street, and it provides great diagrams that can really help practitioners visualize how a street can look and operate,” said Ned Codd, Assistant Secretary for GreenDOT, the state’s transportation sustainability initiative.

It’s going to be a boon for biking and walking activists lobbying for better accommodations on the roads. But those people who can’t help but roll their eyes when they hear claims that “Boston is totally going to become the new Copenhagen” will be less pleased.

Cow paths aren’t the only reason Boston confuses


Lost in Boston? Don’t just blame it on the old cow paths.

The confusing nature of navigating Boston is commonly attributed to the winding, crooked streets — formerly cow paths, or so the legend goes — that curve and jumble with no particular sense of a larger organization, à la the Financial District.

Now, a scientist and data visualizer in Portland, Ore., may have identified another reason why driving, cycling, or walking in Boston can be so mystifying: streets’ lack of orientation to north, south, east, and west.

“If you’re like me, and you use the sun to navigate, you probably appreciate cities with gridded street plans that are oriented in the cardinal directions,” wrote Seth Kadish on his blog, the Visual Statistix, late last month. “If you know that your destination is due west, even if you hit a dead end or two, you’ll be able to get there.”

Kadish came up with a collection of graphs to assess 12 different cities’ adherence to the familiar north-south-east-west directions. Each somewhat like a star, with bars radiating outward at various angles.

The length of each bar corresponds with the number of city streets oriented in that direction on the compass rose. The cities that adhere most strictly to a north-south-east-west grid, such as Denver and Chicago, end up looking like a neat plus-sign.

Others, like Charlotte, N.C., and Honolulu, lack any kind of grid structure and look like an uneven starburst.

“The minimal geographic extents of the grids in Charlotte and Honolulu are completely overwhelmed by the winding roads of the suburbs,” Kadish writes.

But Boston, it turns out, is somewhere in the middle. We do have grids — think the Back Bay — but often, they don’t align with north-south-east-west directions. Many streets, including those in grid formats, actually point northwest, northeast, southwest, and southeast. (We’re looking at you, South End.)

“Downtown Boston has some gridded streets, but the suburban grids are differently aligned, dampening the expression of a single grid on the rose diagram,” Kadish said.

Why does that make it harder for residents and tourists alike to figure out where they’re headed? People tend to think in terms of the four basic cardinal directions: Turn left from a northbound street, and you know you’re headed west — or at least, west-ish. But when grids aren’t laid out flush with cardinal directions, if you don’t have a mental imprint of the city streets, it’s hard to know if “west-ish” will take you to Allston or Jamaica Plain.

(Aside: Did you know there is an aboriginal community in Australia where the language eschews all use of relative directions — words like “left,” “right,” “in front,” “behind” — and relies purely on geographic directions to express spacial relations? Think: “Please pass the pepper, darling — it’s northwest of the salt.”)

Kadish, who attended Brown University in Providence for graduate school, said he knows from firsthand experience how those off-kilter blocks can make for a bewildering navigational experience.

“I was always amazed by the crazy Boston streets,” Kadish wrote in an e-mail. “We used to take the commuter rail up to Boston on weekends. I was always so glad I didn’t have a car there, because driving would have been overwhelming!”

Martine Powers can be reached at Follow her on Twitter @martinepowers.