> And how is this 'difficult'? It seems like it's a trivial software
I co-founded a traffic sensing startup circa 2008. At the time, very few cities had centralized control over their lighting systems (LA mostly did for example, most others did not). In fact, most traffic systems we looked into at the time had very little aggregated control at all. You may see situations were a particular busy street had 'linked' control for a series of 5,6 or 7 block in a row, but even that was fairly rare. Most of the time, each intersection has it's own controller, with minimal if any linkage to the outside world. You can usually find the control boxes, they're the randomly placed conspicuous steel boxes somewhat near the intersection. As for a 'software update', in most cases you were talking about an 8bit 8051 MCU switching some relays. A 'software update' involves someone going to each of these boxes physically (thousands in a decent sized city), plugging into some sort of serial port on the controller board, and running a possibly dangerous destructive write on the MCU flash.
I co-founded a traffic sensing startup circa 2008. At the time, very few cities had centralized control over their lighting systems (LA mostly did for example, most others did not). In fact, most traffic systems we looked into at the time had very little aggregated control at all. You may see situations were a particular busy street had 'linked' control for a series of 5,6 or 7 block in a row, but even that was fairly rare. Most of the time, each intersection has it's own controller, with minimal if any linkage to the outside world. You can usually find the control boxes, they're the randomly placed conspicuous steel boxes somewhat near the intersection. As for a 'software update', in most cases you were talking about an 8bit 8051 MCU switching some relays. A 'software update' involves someone going to each of these boxes physically (thousands in a decent sized city), plugging into some sort of serial port on the controller board, and running a possibly dangerous destructive write on the MCU flash.
It definitely qualifies as 'difficult'