Watch As I Make This Standard Disappear

By John Carr, NMA Massachusetts Activist

“Is it true that long ago firemen put fires out instead of going to start them?”Fahrenheit 451, Ray Bradbury

My city ended its moratorium on illegal stop signs.

I suspect what happened is, the new city engineer in Newton learned a trick from his counterpart next door in Waltham who got it from the town engineer in Wellesley, who found the excuse he needed to give selectmen the stop sign they wanted.

All way stop signs aren’t supposed to be posted unless certain measurable criteria are met. The intersection has to be objectively, not subjectively, busy or dangerous. The objective criteria are called “warrants.” This many crashes, that many seconds of delay, and so forth.

The rules are found in the Manual On Uniform Traffic Control Devices. Local politicians hate the MUTCD because they can’t get their way. A few years ago the National Motorists Association started reminding Massachusetts cities of the rules. The city solicitor in Newton backed me up. He told the Board of Aldermen to stop approving illegal stop signs.

Politicians hated the MUTCD even more and kept up the pressure. One engineer caved, and another followed, and another.

New neighbors

A Waltham, Massachusetts city councilor had four way stop signs posted around the corner from me six years ago. Last year the city engineer was asked to retroactively approve the stop signs. He was in a difficult position because professional standards said the signs were not needed. A state DOT engineer reassured him nobody enforced sign rules. So he approved a bunch of illegal signs.

His report conceded the intersection did not meet warrants. He made up a different rule. The sight line from behind the eastbound stop bar to traffic approaching from the south was blocked by shrubs. The politician who wanted the signs was right! He’s so smart.

The intersection doesn’t really need stop signs. The shrubs were an excuse.


I always carry a camera. I took a picture of the new stop signs in 2007 and filed it away. I took another picture when the engineer’s report came out.

The offending shrubs did not exist when the stop signs were posted. Somebody planted them before the engineer went out to measure sight lines.

It’s illegal to obstruct corners, by planting shrubs or otherwise, on private or public property. The report should have said, vegetation needed pruning. Most DPWs consider that routine maintenance.

And why was the stop line 15 feet away from the intersection? It doesn’t have to be that far away. The measured sight line would be better if it were closer.

If the DPW did its job the engineer wouldn’t have an excuse, and city councilors would be annoyed. I’m reminded of Ray Bradbury’s Fahrenheit 451, where the job of firemen is to start fires.

No excuses

As a PR exercise the report seems to have worked. But it wasn’t engineering.

Because of the potential for abuse, Massachusetts does not allow exceptions to warrants. State rules say “Multi-way Stop Signs must meet the warrant criteria as outlined in Section 2B.07 of the 2009 MUTCD.” The intersection was only half as busy as the absolute minimum for all way stop signs, and there were no accidents. So the signs are illegal.

Your state may allow exceptions to warrants, and you may see the same excuse used. I know the same excuse has been used elsewhere because Pennsylvania decided to explicitly prohibit it (67 Pa. Code 212.106(c)(2). I’ll explain why the report also fails under the lax federal rules.

An ordinary intersection becomes extraordinary

MUTCD stop sign warrants are in a category of rules called “guidance.” Despite the name these rules are mandatory in “typical” situations. Exceptions are allowed if an engineer finds the situation to be atypical.

Not having 200 feet of sight distance from 15 feet behind the curb line is typical. It does not excuse breaking the rules.

The Boston area became urbanized long before the concepts of sight distance and design speed were invented. Most intersections fail the “sight distance from behind the stop bar” test. Any street with parking fails the test, because a legally parked truck blocks sight lines. This is confirmed by the Waltham engineer’s report, which found most intersections to be deficient, and my own measurements and observations.

Setting the bar

Why measure sight distance from behind the stop bar? The all way stop sign rules don’t mention the stop bar. It’s an arbitrary line on the pavement. In an old city drivers pause near the edge of the road no matter where the stop bar is. The wait–go decision (“gap acceptance”) at the edge of the road is where you would like to be seen.

True sight distance is three times as great as the report says. (I measured.) When the nose of the car is still behind the curb line you can see it from plenty far away. The accident history backs me up. There is no safety problem.

What happened here is a standard meant for road design was selectively misappropriated for use in traffic regulation, which has a different set of standards. By another design standard the intersection could have no stop signs. It didn’t have any until the 1960s. That’s politically unacceptable today.


A friend used to get pulled over in Waltham because “your car matches the description of one that was stolen.” Not really. There are thousands of old BMWs on the road. He got pulled over because he was young and looked like trouble.

The sight distance excuse is just as much a pretext. The city would have hundreds of all way stops if it the rule were applied consistently. Sometimes hedges abut the road, making pulling into traffic a frightening experience. (map 1, map 2) Sometimes the intersection is absolutely ordinary. But that doesn’t matter. The real process is political.


Let me rephrase what I wrote last year about judging approval of regulatory signs and signals:

• Know the warrants. Federal rules apply, and your state may have additional rules. Sometimes there are no warrants. For example, designation of one way streets is a political decision.
• Compare the hard data in the engineer’s report to the warrants. Close doesn’t count; warrants are minimums. What would you recommend?
• Is the official excuse really a special case, or would it apply so often that the exception swallows the rule?

In my city only one of many stop sign studies passed this test. But their record is still perfect. That justifiable stop sign was posted on a state highway without a state permit, making it illegal too.

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