nodnirG kraM wrote:I often wonder who is in control of these signs. The M25 in particular enjoys giving misinformation on its VMSs. Whether it be QUEUE CAUTION accompanied by flashing 50 advisory limits when there is barely any traffic let alone queues; DEBRIS IN CARRIAGEWAY when there is none; or maybe the obligitory FOG on the clearest day you could imagine, generally I tend to disbelieve any message I see on that road.
Is someone sitting in a control room somewhere, bored, trying to entertain themselves? Or are they automated when there's a certain traffice volume? I know the Variable Speed Limits and Ramp Metering are semi-automatic when traffic builds up, but on non variable sections, does someone get to decide when QUEUE AFTER NEXT JCTN is used?
Is this a question for SABRE? Becuase I can't remember my password.
Oh yeah, and do they just get to choose from a list of prescribed messages, or can they be creative? Could a message say "YOU'D BE QUICKER WALKING" for example? If that were my job, I'd feel it necessary to put jokes up in a queue. You know, the first sign says KNOCK KNOCK, the next one says WHO'S THERE? etc. Or perhaps I could at least put up the reason I've been sitting in a queue for four hours. QUEUE AHEAD is of little use when I'm already in it. Why can't it read QUEUE AHEAD BECAUSE SOME DICK IN A BMW WAS CHATTING ON HIS PHONE WHILST ADJUSTING HIS UNDERWEAR WITH THE OTHER HAND AND THEN SPILT COFFEE ON HIS LAP BECAUSE HE'S JUST THAT MUCH OF A DICK. HE'S OKAY BY THE WAY, JUST MINOR INJURIES. SERVES HIM RIGHT I SUPPOSE. DICK.
From what I have read the M25 signs work on the basis of slowing traffic down to avoid causing a bottleneck. So they detect the level of traffic is above a threshold and reduce the speed limit in the immediate area to 40mph (the lowest the system is allowed to do), 50mph further out and 60mph further from that. From what I read if the system works well it actually avoids you actually coming to a standstill.
The entire system appears to be automated without needing intervention.
Bizarre.
