Firefly,
Every single intersection is operated by a computer that talks to all of the lights at each intersection. For half the city, as Nufy pointed out, this computer is a computer located at the Manchester building (I think, haven't been there, although I'm planning a visit). For the rest of the city there is a control cabinet at the actual intersection. This control cabinet does a number of things, but one of those things is make sure that the lights in one direction are never green when the lights in the perpendicular direction are green. Now, with the cameras, that control cabinet is even more impressive, and costly. I've been told the higher end computers (we designed for them at the new lights in Chestermere) will put you back about $50,000.
As for the cost to build an entire intersection (mast arms, signals, cameras, control cabinet) it's about $250,000. It gets to be even more when you include advance warning signals.
|