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

[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.