Speed Cameras Around Philadelphia?

[Michael in Philly]

I don't see - somewhat to my surprise - any discussion of this; I apologize if I missed it.
Over the last few months, these sort of overhead bars with small cubical things hanging from them over each lane, have been appearing along I-95 through and near Philadelphia.  Think I've seen one or two on the Schuylkill as well.  I'm guessing they're speed cameras?  I can't imagine what else they'd be.

I keep passing under them at, like, 70 (the limit's 55), because I forget they're there until I'm directly under them, saying to myself "oh, sh..," and expecting tickets to arrive in the mail.  Nothing yet - fingers crossed - but does anyone know whether I'm right about what they are?  And have inside information on the tolerance?

[Truvelo]

Are you sure they're speed cameras? We have them here and I've seen them in other countries too. They tend to be licence plate recognition and traffic flow cameras. The former have often appeared as a result of 9/11.

[Michael in Philly]

Are you sure they're speed cameras? We have them here and I've seen them in other countries too. They tend to be licence plate recognition and traffic flow cameras. The former have often appeared as a result of 9/11.

No I'm not sure; it was a guess.

In fact, I just found this:  http://www.poi-factory.com/node/31239

[brownpelican]

Do they look like this?

New Orleans traffic camera

[Hot Rod Hootenanny]

I'd say traffic flow, especially since there aren't any traffic lights along I-76 or I-95.
As for speed, they would need two landmarks so they could time you, unless you got laser shooting cameras there.

[PAHighways]

Those are ITS related, not for speed enforcement.

[Michael in Philly]

Glad to hear it, because a 55-mph limit is just silly.  What's ITS?

[The Premier]

Glad to hear it, because a 55-mph limit is just silly.  What's ITS?

Integrated Transportation System. They are used to detect traffic flow.

[PAHighways]

Glad to hear it, because a 55-mph limit is just silly.  What's ITS?

Intelligent Transportation System

[hm insulators]

Glad to hear it, because a 55-mph limit is just silly.  What's ITS?

Intelligent Transportation System

So why is it called the "Intelligent Transportation System" when so many drivers are so dumb?

[PAHighways]

Glad to hear it, because a 55-mph limit is just silly.  What's ITS?

Intelligent Transportation System

So why is it called the "Intelligent Transportation System" when so many drivers are so dumb?

It just describes the electronics.