M4 Smart motorway speed limit
Discussion
I was pleasantly surprised to find all the gantries switched off yesterday morning from M4 J10 until the roadworks near Slough. Took me a minute to notice, where upon I cranked the cruise up to 80 from the paltry 65 I had got used to.
What's the craic? I had read that the seemingly constant 60 limit since they finished the road works was to reduce emissions. Makes sense but I'd rather make progress when there's 4 lanes of brand spanking motorway to use.
Had thought perhaps it was a temporary glitch yesterday, but they were still off this morning. With the 60 limit I wasn't entirely sure how it was enforced. The yellow 'temporary' cameras are still in place, and had presumed they still work on average speed basis.
Without a variable limit displayed is it now fair game? Can I take my chances and watch out for speed enforcement as per the good old days, or are the gantries live somehow?
What's the craic? I had read that the seemingly constant 60 limit since they finished the road works was to reduce emissions. Makes sense but I'd rather make progress when there's 4 lanes of brand spanking motorway to use.
Had thought perhaps it was a temporary glitch yesterday, but they were still off this morning. With the 60 limit I wasn't entirely sure how it was enforced. The yellow 'temporary' cameras are still in place, and had presumed they still work on average speed basis.
Without a variable limit displayed is it now fair game? Can I take my chances and watch out for speed enforcement as per the good old days, or are the gantries live somehow?
There’s no warning of an average speed check any more from 8/9 to 12, so those cameras must be turned off.
I assume the new Hadecs cameras are now live, so wouldn’t pass any of them at more than 10%+2 of the currently active limit. There are a lot of them, twin yellow boxes on the side of gantries.
I assume the new Hadecs cameras are now live, so wouldn’t pass any of them at more than 10%+2 of the currently active limit. There are a lot of them, twin yellow boxes on the side of gantries.
Are they live when nothing is displayed on the gantries?
I've been sticking to 65 on the clock for the past few months when the gantries have displayed 60 limit. Seen the odd vehicle completely ignoring this and sailing through at 70 I'd estimate.
Surely if there is not a reduced limit the gantries should display a national speed limit sign or 70? They've been completely blank last couple of days.
The 60 limit just seems ridiculous with 4 lanes and everyone crowded jnto lanes 3 and 4. Even lorries are cruising in lane 3 as the few cars in lane 2 are going so slow. Obviously no one is in lane 1!
I've been sticking to 65 on the clock for the past few months when the gantries have displayed 60 limit. Seen the odd vehicle completely ignoring this and sailing through at 70 I'd estimate.
Surely if there is not a reduced limit the gantries should display a national speed limit sign or 70? They've been completely blank last couple of days.
The 60 limit just seems ridiculous with 4 lanes and everyone crowded jnto lanes 3 and 4. Even lorries are cruising in lane 3 as the few cars in lane 2 are going so slow. Obviously no one is in lane 1!
I travel on the M4 every day into london and the cameras are live.
I see them flashing every day with people flying past me while im stuck on Cruise at 70.
Ive literally had people fly past me at 100 ish, then slam on the brakes before getting to the gantry but it still goes off. From that i would assume they are doing an average calculation between gantrys.
I see them flashing every day with people flying past me while im stuck on Cruise at 70.
Ive literally had people fly past me at 100 ish, then slam on the brakes before getting to the gantry but it still goes off. From that i would assume they are doing an average calculation between gantrys.
Saabaholic said:
I travel on the M4 every day into london and the cameras are live.
I see them flashing every day with people flying past me while im stuck on Cruise at 70.
Ive literally had people fly past me at 100 ish, then slam on the brakes before getting to the gantry but it still goes off. From that i would assume they are doing an average calculation between gantrys.
I'm pretty sure the yellow cameras bolted to the side of the gantries are the same set up as on the M25, and work on an instantaneous speed, not an average. If it were an average, they already have a record of your number plate in and out of that section, hence wouldn't need to take a 'photo' so to speak....?I see them flashing every day with people flying past me while im stuck on Cruise at 70.
Ive literally had people fly past me at 100 ish, then slam on the brakes before getting to the gantry but it still goes off. From that i would assume they are doing an average calculation between gantrys.
MattyD803 said:
I'm pretty sure the yellow cameras bolted to the side of the gantries are the same set up as on the M25, and work on an instantaneous speed, not an average. If it were an average, they already have a record of your number plate in and out of that section, hence wouldn't need to take a 'photo' so to speak....?
Agreed, those are definitely not average speed cameras and will only flash if you're over whatever limit they're set to. There are still some average speed cameras active between J8/9 and the M25, but those don't flash. BrightYellowTVR said:
The yellow cameras on the side of the gantry are live 24x7 I got done at 81mph at midnight and had to attend a speed awareness course.
Was just saying to my wife I was wondering how you're doing and up you pop on here. Sorry to hear about getting pinged, though at least getting the course saves points on your licence.I was a bit suspicious the first time I came back along the M4 from Newbury direction and noticed that the '60' signs weren't lit up, so it took me a while risk going up to 70. I'm sure I've seen those yellow cameras flash at cars doing very little more than the prescribed limit (ie they were just creeping past me), so I'm extra wary of them myself.
Back when it was a longer section of 50 average I was often surprised at cars coming past at (guessing) 70mph. Sometimes the same cars would brake heavily as they passed the average cameras. I know sometimes they prick the driver's conscience, but speeding back up straight after just makes me wonder how thick they must be...
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