Just to add to this: Current traffic light controllers and/or vehicle detection system (VDS) units are also fairly ruggedised: they're designed to live in outd

Just to add to this: Current traffic light controllers and/or vehicle detection system (VDS) units are also fairly ruggedised: they're designed to live in outdoor cabinets with minimal active cooling, survive up to +50C (or more) while still operating, and have long replacement lifecycles. Modern equipment capable of processing imagery "in the field" - some kind of x86 machine - would have a hard time meeting these requirements for the same cost. Ruggedised machines do exist, but at a significant price premium. The other option would be to ship that data back over fibre (common), but that also creates a dependency issue on the network and may require network hardware upgrades to deal with the big increase in h.264 encoded video traversing the network. I'd love to see more of this happening, but it's an extremely conservative industry/market.