Smart motorways - constant speed changes
Discussion
Driving on the M25 on Tuesday I had the unfortunate experience of driving through a ‘smart’ section leading up to the Dartford tunnel. The conditions were pretty awful, heavy rain, lots of surface spray, heavy traffic.
Throughout the lead up to the tunnel the gantries were shifting every gantry from 40mph - 60mph - 50mph etc. I found myself watching my speedo far more than I would have liked in fear of getting a speeding ticket when really I needed to concentrate on the cars ahead.
Who is it that sets these speeds? I have appreciated their impact on other motorways when there has been a consistent speed reduction leading to a steady flow but this was a mess and quite stressful.
Throughout the lead up to the tunnel the gantries were shifting every gantry from 40mph - 60mph - 50mph etc. I found myself watching my speedo far more than I would have liked in fear of getting a speeding ticket when really I needed to concentrate on the cars ahead.
Who is it that sets these speeds? I have appreciated their impact on other motorways when there has been a consistent speed reduction leading to a steady flow but this was a mess and quite stressful.
AJB88 said:
Same people that set the 50mph between MK and Luton every night at 3am-5am when the road is completely clear and no works taking place.
So it is a person? I wondered whether it was done automatically, maybe by radar working out how many cars were passing or something. Is this regulated or monitored? I can’t understand how actual people could do this.AJB88 said:
I'm not actually sure to be honest but its annoying as hell doing the 3:30am airport run to find a 50 or 40 mph limit on a motorway which should be 70mph when its dry and no road works taking place etc.
Wow, that is annoying. I can’t see this continuing without a court case proving their inappropriate or misuse as in the 3.30am example or where it has caused an accident as in my case.I've explained this so many times..................................
Check first to see what the message along with the speeds says, if it's ANYTHING to do with "QUEUE" then it's an automatic setting set my MIDAS (Go Google it)
Basically, set into the c/way surface are detectors (Similar to those you see in front of traffic lights) these monitor the average speed of the traffic going over them (amongst a lot of other stuff that doesn't affect the signals) If the traffic has slowed down to a certain level, then it will put speeds on the signals with "QUEUE CAUTION" (or similar) on the message sign. The system checks the detectors approx every 4 mins, if traffic has passed over the pads higher than the trigger speed, it will either raise the speed on the signals, or clear them completely. So you can be sure that traffic congestion has triggered them.
Now if they're up & down as you state, then there are bunches of slow traffic moving along (possibly a group of HGV's going up hill?)
If however the message if of some type of incident, then the signals would have been set manually, BUT for 'unconfirmed' incidents they would normally be set to 50, although MIDAS can reduce them (usually no slower than 40 unless there is a mandator lower speed than normal, ie a tight slip-road)
Confirmed incidents could have much lower speeds set, lane closures etc. (Incidents have to be confirmed by a reliable source, or cctv, not just Joe Public)
The HE are getting the message signs reprogrammed with "REPORT OF" for unconfirmed incidents.
So shortly for unconfirmed stuff, you should be seeing something like "REPORT OF PEDESTRIANS" "REPORT OF ANIMALS" "REPORT OF ACCIDENT" Along with the speed setting.
This means that you may not find anything if it's been reported in the wrong location / c-way/ motorway, or you could even find the whole c/way blocked. MIDAS would reduce the original 50's signals down to 40's if traffic has slowed down.
Once the incident is found and confirmed then the signals & message signs would be altered appropriately.
Check first to see what the message along with the speeds says, if it's ANYTHING to do with "QUEUE" then it's an automatic setting set my MIDAS (Go Google it)
Basically, set into the c/way surface are detectors (Similar to those you see in front of traffic lights) these monitor the average speed of the traffic going over them (amongst a lot of other stuff that doesn't affect the signals) If the traffic has slowed down to a certain level, then it will put speeds on the signals with "QUEUE CAUTION" (or similar) on the message sign. The system checks the detectors approx every 4 mins, if traffic has passed over the pads higher than the trigger speed, it will either raise the speed on the signals, or clear them completely. So you can be sure that traffic congestion has triggered them.
Now if they're up & down as you state, then there are bunches of slow traffic moving along (possibly a group of HGV's going up hill?)
If however the message if of some type of incident, then the signals would have been set manually, BUT for 'unconfirmed' incidents they would normally be set to 50, although MIDAS can reduce them (usually no slower than 40 unless there is a mandator lower speed than normal, ie a tight slip-road)
Confirmed incidents could have much lower speeds set, lane closures etc. (Incidents have to be confirmed by a reliable source, or cctv, not just Joe Public)
The HE are getting the message signs reprogrammed with "REPORT OF" for unconfirmed incidents.
So shortly for unconfirmed stuff, you should be seeing something like "REPORT OF PEDESTRIANS" "REPORT OF ANIMALS" "REPORT OF ACCIDENT" Along with the speed setting.
This means that you may not find anything if it's been reported in the wrong location / c-way/ motorway, or you could even find the whole c/way blocked. MIDAS would reduce the original 50's signals down to 40's if traffic has slowed down.
Once the incident is found and confirmed then the signals & message signs would be altered appropriately.
Gafferjim said:
If however the message if of some type of incident, then the signals would have been set manually, BUT for 'unconfirmed' incidents they would normally be set to 50, although MIDAS can reduce them (usually no slower than 40 unless there is a mandator lower speed than normal, ie a tight slip-road)
Confirmed incidents could have much lower speeds set, lane closures etc. (Incidents have to be confirmed by a reliable source, or cctv, not just Joe Public)
The HE are getting the message signs reprogrammed with "REPORT OF" for unconfirmed incidents.
So shortly for unconfirmed stuff, you should be seeing something like "REPORT OF PEDESTRIANS" "REPORT OF ANIMALS" "REPORT OF ACCIDENT" Along with the speed setting.
This means that you may not find anything if it's been reported in the wrong location / c-way/ motorway, or you could even find the whole c/way blocked. MIDAS would reduce the original 50's signals down to 40's if traffic has slowed down.
Once the incident is found and confirmed then the signals & message signs would be altered appropriately.
Seen the 'report of' signs recently, don't think it's a bad idea. Confirmed incidents could have much lower speeds set, lane closures etc. (Incidents have to be confirmed by a reliable source, or cctv, not just Joe Public)
The HE are getting the message signs reprogrammed with "REPORT OF" for unconfirmed incidents.
So shortly for unconfirmed stuff, you should be seeing something like "REPORT OF PEDESTRIANS" "REPORT OF ANIMALS" "REPORT OF ACCIDENT" Along with the speed setting.
This means that you may not find anything if it's been reported in the wrong location / c-way/ motorway, or you could even find the whole c/way blocked. MIDAS would reduce the original 50's signals down to 40's if traffic has slowed down.
Once the incident is found and confirmed then the signals & message signs would be altered appropriately.
I've been along the M25 past midnight before and the speed limit on a 4 lane section was 40. No reason given, I could see a handful of cars. I use the M6 through Birmingham on Christmas morning on my annual pilgrimage north and have only ever seen 60 on the signs since the road was down graded to a smart motorway. Same with the M1 heading south of the M6, only ever shows 60 no matter how light the traffic is. We were supposed to be getting the limit increase to 80, but now it's slower and enforced with cameras. The trip north on Christmas morning takes me longer every year. I won''t mention the record breaking length of time to get home this year. Ok, I will. 5.5 hours to do 180 motorway miles. Thanks.
To be honest I don’t think any of that applies. The traffic was 4, sometimes 5 lanes, HGVs were mostly in lane 1,2 and sometimes 3. There was no incident and there was no reason for the traffic to be bunched in slower or faster moving groups.
My main concern is shifting from looking at the cars ahead and anticipating the traffic to watching my speedo, checking the gantries in front and looking for whether there are speed cameras attached. I prefer driving at peak times in Barcelona and Paris to this nannying, interference.
My main concern is shifting from looking at the cars ahead and anticipating the traffic to watching my speedo, checking the gantries in front and looking for whether there are speed cameras attached. I prefer driving at peak times in Barcelona and Paris to this nannying, interference.
Tri-Star said:
Driving on the M25 on Tuesday I had the unfortunate experience of driving through a ‘smart’ section leading up to the Dartford tunnel. The conditions were pretty awful, heavy rain, lots of surface spray, heavy traffic.
Throughout the lead up to the tunnel the gantries were shifting every gantry from 40mph - 60mph - 50mph etc. I found myself watching my speedo far more than I would have liked in fear of getting a speeding ticket when really I needed to concentrate on the cars ahead.
Who is it that sets these speeds? I have appreciated their impact on other motorways when there has been a consistent speed reduction leading to a steady flow but this was a mess and quite stressful.
Agreed. It does make for speedo watching, which is dangerous when there is usually someone about to pull out on you.Throughout the lead up to the tunnel the gantries were shifting every gantry from 40mph - 60mph - 50mph etc. I found myself watching my speedo far more than I would have liked in fear of getting a speeding ticket when really I needed to concentrate on the cars ahead.
Who is it that sets these speeds? I have appreciated their impact on other motorways when there has been a consistent speed reduction leading to a steady flow but this was a mess and quite stressful.
Gafferjim said:
I've explained this so many times..................................
Check first to see what the message along with the speeds says, if it's ANYTHING to do with "QUEUE" then it's an automatic setting set my MIDAS (Go Google it)
Basically, set into the c/way surface are detectors (Similar to those you see in front of traffic lights) these monitor the average speed of the traffic going over them (amongst a lot of other stuff that doesn't affect the signals) If the traffic has slowed down to a certain level, then it will put speeds on the signals with "QUEUE CAUTION" (or similar) on the message sign. The system checks the detectors approx every 4 mins, if traffic has passed over the pads higher than the trigger speed, it will either raise the speed on the signals, or clear them completely. So you can be sure that traffic congestion has triggered them.
Now if they're up & down as you state, then there are bunches of slow traffic moving along (possibly a group of HGV's going up hill?)
You may have explained it, but the system is still unjustifiably fCheck first to see what the message along with the speeds says, if it's ANYTHING to do with "QUEUE" then it's an automatic setting set my MIDAS (Go Google it)
Basically, set into the c/way surface are detectors (Similar to those you see in front of traffic lights) these monitor the average speed of the traffic going over them (amongst a lot of other stuff that doesn't affect the signals) If the traffic has slowed down to a certain level, then it will put speeds on the signals with "QUEUE CAUTION" (or similar) on the message sign. The system checks the detectors approx every 4 mins, if traffic has passed over the pads higher than the trigger speed, it will either raise the speed on the signals, or clear them completely. So you can be sure that traffic congestion has triggered them.
Now if they're up & down as you state, then there are bunches of slow traffic moving along (possibly a group of HGV's going up hill?)
king ridiculous isn't it? I've experienced the same thing on the M25 many times; speed limit signs displaying 40/50/60 in a seemingly random sequence. Often the traffic conditions at that point on the road could allow progress at a faster rate (I realise that the signs are there to prevent congestion further along the road) so it results in drivers constantly looking for the next sign or at their speedo rather than on the road itself, their mirrors, etc. It might look good in a control room and be the most effective system at reducing delays, but from a driver's viewpoint it looks like an over-eager system designed by someone that doesn't know what they're doing, and just adds to the mentality that the variable speed limits are only there for sinister purposes. In the grand scheme of things, that's far worse than a slightly longer delay.There should, IMO, never be an occasion when the speed limit on a motorway is reduced to 40. There is simply no reason for it. The algorithms ought to be updated so that there's no flitting between a 50 and 60. If the limit needs to be reduced to 50, it should only be able to go 60 - NSL at the end of that section (even if there are multiple 60 signs), not 60 for a while then back to 50. Encouraging repeated changes up and down in speed is part of the problem, not part of the solution. The signs also need fixing so that it's easier to differentiate between a 5 and a 6. And lastly the sensors need to stop lowering the speed limit for the entire motorway because traffic is slowing on the inside lane approaching an exit slip road. Sort all of that and people will start to trust and understand variable speed limits.
To be honest I don’t think any of that applies. The traffic was 4, sometimes 5 lanes, HGVs were mostly in lane 1,2 and sometimes 3. There was no incident and there was no reason for the traffic to be bunched in slower or faster moving groups.
My main concern is shifting from looking at the cars ahead and anticipating the traffic to watching my speedo, checking the gantries in front and looking for whether there are speed cameras attached. I preferred driving at peak times in Barcelona and Paris to this nannying, interference.
My main concern is shifting from looking at the cars ahead and anticipating the traffic to watching my speedo, checking the gantries in front and looking for whether there are speed cameras attached. I preferred driving at peak times in Barcelona and Paris to this nannying, interference.
Gafferjim said:
The HE are getting the message signs reprogrammed with "REPORT OF" for unconfirmed incidents.
So shortly for unconfirmed stuff, you should be seeing something like "REPORT OF PEDESTRIANS" "REPORT OF ANIMALS" "REPORT OF ACCIDENT" Along with the speed setting.
Not shortly, those reasons codes are now active and being used successfully. Operator sets a speed on a signal (40 or 50 or whatever) with a reason code of 'Report of Animals' and the message sign displays the necessary message automatically.So shortly for unconfirmed stuff, you should be seeing something like "REPORT OF PEDESTRIANS" "REPORT OF ANIMALS" "REPORT OF ACCIDENT" Along with the speed setting.
Edited by chopper602 on Thursday 4th January 13:28
spikyone said:
There should, IMO, never be an occasion when the speed limit on a motorway is reduced to 40.
So a serious accident in Lanes 1 and 2 and you'd still like the traffic to be rushing by in lanes 3 and 4 at 50/60mph then?(not that, that would happen as they'd all be slowing down for a good look!)
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