Speed traps?

[bobobb.livejournal.com]

My friend said that she was driving on Broadway last night and saw a bunch of blue lights on video cameras pointed at intersections.  Are these speed traps or cameras snapping pictures of people who run red lights?

Comments

[inahandbasket]

erm, the snow emergency lights?

[ron_newman]

Did she not see the sign next to each blue light, that says "SNOW EMERGENCY WHEN FLASHING" ?

I don't think the state legislature has permitted red-light cameras yet. I hope they continue to refuse, because they are a bad idea.

[cnoocy]

Two nights ago, I was on foot across the street, standing still and trying to make out one of those signs and could not read it at all. It's really difficult to read a sign that's next to, but not well illuminated by, a bright flashing light.

[tfarrell.livejournal.com]

I don't know if they're legal either, but http://www.trapster.com/ has reports claiming the existence of several, including one in Somerville... it's allegedly in union square though, at the intersection of Somerville Ave and Washington St.

[rax.livejournal.com]

It's possible these are light control cameras and not speed/light trap cameras. I know that the intersection of Highland and Willow, for example, has some sort of mechanism that detects cars coming up Willow and gives them the light at off-peak hours. I think it's a camera but I am not 100% sure. (Why would I notice such a thing? It doesn't detect bikes. So I either sit there and wait for a car to show up or eventually get bored and just run the red.)

[ron_newman]

I thought that was done by magnetic loops under the pavement, though.

[rax.livejournal.com]

I know that's the case some places (not Somerville, but Beacon St. in Brookline comes to mind), but in a couple of places I really thought it was cameras. I might be crazy though. :)

[benndragon.livejournal.com]

I thought there were such things as emergency vehicle lights - I've seen all the traffic lights go red and those little lights start flashing, shortly followed by a flashing-lights vehicle zooming through. I could be wrong as well, though.

[ron_newman]

I've seen that at the firehouse in Teele Square, but thought that was done by someone pushing a button inside the fire station.

[benndragon.livejournal.com]

This was a normal two-street intersection in Waltham with no fire-station nearby, rather than the blinky-yellow lights you see in front of almost every fire-station. I think it was a traffic signal preemption (http://en.wikipedia.org/wiki/Traffic_signal_preemption) device (scroll down a bit and you'll see the thing that sits on the traffic light).

[ron_newman]

They should put those on MBTA buses.

[benndragon.livejournal.com]

Didja notice this link (http://en.wikipedia.org/wiki/Bus_priority) at the bottom of that page? Sadly I don't think it would fly around here - we just have to rely on their Boston driving skills. . .

[ron_newman]

It would be worth experimenting with, maybe in Union Square? Wonder if the city would be willing to try it there.

[alphacygni]

Silver Line Washington Street has some traffic signal integration. That's it so far. The jurisdictional issues are difficult.

[roosto.livejournal.com]

I've read articles in the Globe about how the MBTA would like to put some signal priority system in for the Green Line. The city keeps refusing to do it. Has anything about this come up in the Green Line extension meetings? The trolleys that do not have their own right of way tracks ie everything except the D-Line could sorely use this.

[dcltdw]

Not sure if we're thinking of the same thing, but some streetlights have small cameras that detect emergency vehicles. My understanding is that the vehicles have a particular device that gives off a particular strobe pattern in the non-visible spectrum, which the camera detects, and says "aha!" and changes lights accordingly.

Part of my vague understanding is that in some cities, busses are similarly equipped.

Back to EMS, I remember one story about how crews would have to use an A/B box, because the strobe patterns were set differently in adjacent towns.

Anyways, more anecdotes that are probably irrelevant... :)

[nalz.livejournal.com]

I think that both things exist. Most streets definitely use magnetic loops. I've only seem the light cameras for emergency vehicles, though. The camera detects the strobe like you said, although I've never heard of buses using them.

This page actually does a good job of showing what the little cameras look like: http://www.milton.ca/fire/fireoperations/signalchange.htm

As an aside to that - There was a guy a while back in Colorado (I think) that had one and used it when he was commuting because he was always running late. It took the city a while to find him but they eventually did because it happened at the same intersections every day around the same time.

Ah, found the article: http://www.news4jax.com/automotive/8768516/detail.html

[boblothrope.livejournal.com]

There are cameras that detect non-emergency vehicles to make traffic lights change, but I've never seen one on a public road in the eastern U.S.

[mollyrazor.livejournal.com]

Come to Maine and you will see some. We have them at several intersections in Portland.

(I know that's what they are, because when they were installed at the most ridiculous intersection in town people freaked out all OMG THEY'RE SPYING ON US and the city was all, um, no, we are trying to make traffic flow better.)

[concrete.livejournal.com]

used to be, but traffic engineers find cameras are better and easier than loops.

[diatomacearth.livejournal.com]

...Concrete? Like the comic, yes?

[tfarrell.livejournal.com]

Somerville generally uses a sensor embedded in the street to detect the presence of cars at an intersection to control the lights. At intersections that have it that haven't been re-paved since, you can see a large rectangle cut into the street and then closed up, where the sensor was put in. This is why sometimes a light will refuse to change, because either the driver hasn't pulled over the sensor (happens if they're too far back) or because the car is so darn small and made with so much plastic that it doesn't actually register.

I think it's a magnetic sensor.

[rax.livejournal.com]

So I'm going to need to eat a whole lot of cookies if I want that light to ever change for me. I'll get right on it. Thanks!

[nalz.livejournal.com]

Only if they're metal cookies. Ouchers. You could try one of these: http://www.thelightchanger.com/ Some people say they work, others claim crap.

[nalz.livejournal.com]

You're right, they are electro-magnetic sensors. And they are often the bane of my commuting existence when I'm on my motorcycle.

[ron_newman]

In some states, the law has simply been changed to allow a motorcycle to treat a red light as a stop sign. That makes more sense than trying to re-engineer lots of traffic signals to be able to detect motorcycles (and bicycles), and it doesn't cost anything.

[nalz.livejournal.com]

I agree. I wish all states would pass these kinds of laws, and other more moto-friendly laws that make sense.

[boblothrope.livejournal.com]

It's not that hard to have a loop detector that can sense a bicycle -- the ones in Cambridge do (that is, the few remaining loops that aren't either broken entirely, or turned off and replaced by fixed timers).

It helps if you can see where the loop is, or if they paint a small bicycle symbol on the pavement to show you where to wait.

[ron_newman]

True, but why spend money to re-equip all those loop detectors when you can just change the law for no money at all?

[boblothrope.livejournal.com]

Because if the intersection needs a light, then the eventual green light would be helpful for the bicycle or motorcycle.

If traffic is light enough that drivers can easily get across without too long of a wait, even at busy times of day, there shouldn't be a traffic light in the first place.

[ron_newman]

Since bicycles and motorcycles are small and easily maneuverable, they can safely cross through gaps in traffic that would be unwise for the driver of a car. They can also cross just part of an intersection at a time, if necessary.

[ukelele.livejournal.com]

Or because it's a bike (possible to trigger those with a bike, but hard, and they're inconsistent). Sigh.

[bobobb.livejournal.com]

I've never heard of that before....
Is there a point other than to tell us...um...there is snow?

[chenoameg.livejournal.com]

The idea is that upon driving back to Somerville you should see the blinking light if a snow emergency is in progress and know you can't park on the even side of any streets.

[ron_newman]

http://davis_square.livejournal.com/tag/snow+emergency

[philbot.livejournal.com]

It means your friend is pregnant.

[sapphira-altair.livejournal.com]

Win.

[ron_newman]

Or that you should run to the nearest K-Mart at once.

[hrafn.livejournal.com]

Those are the larval form of the Giant Wind Turbine of Doom!! Soon, we too will look like the Meadowglen Mall. :( :( :(

[benndragon.livejournal.com]

From this post (http://community.livejournal.com/davis_square/1625654.html) yesterday:
In addition, flashing blue lights installed at 22 key intersections and entryways to the City will be activated immediately after the declaration of a snow emergency, and remain lit for the duration of the snow emergency.

[olszowka.livejournal.com]

While most of the existing traffic sensors for traffic signals use the induction coil in the pavement method, the current state of the art is machine vision systems. They are less subject to damage from weather, overweight trucks, etc. and a single well-aimed camera can count the queue length and thus substitute for several coils.