'Smart' M1 speed cameras on Sheffield stretch on 24-hours-a-day

[grand]

so how do the cameras work then? are they some kind of average speed camera

[peak4]

so how do the cameras work then? are they some kind of average speed camera

 

Have a look at This Link for an explanation.

[grand]

Very sneaky i agree with them when matrix are on to a set limit ect .. Are when one lane is closed but shouldnt be running 24/7

[forgeman]

What about the difference in the circumference of a new tyre tread to a well worn but legal one. Surely there would be at least a one mph difference. Sadly I'm not clever enough to work that one out.

[truman]

What about the difference in the circumference of a new tyre tread to a well worn but legal one. Surely there would be at least a one mph difference. Sadly I'm not clever enough to work that one out.

 

I assume the speedo's are designed with new tyres in mind..you'll be going slower with worn ones so shouldn't cause an issue..

[barleycorn]

One would assume the speedo is calibrated on new tyres. When the tyres become worn the diameter, and hence the circumference, will decrease meaning you travel less distance per revolution, i.e. slower.

[SnailyBoy]

Very sneaky i agree with them when matrix are on to a set limit ect .. Are when one lane is closed but shouldnt be running 24/7

 

Just imagine the matrix says 70, unless stated otherwise.

Edited February 6, 2018 by SnailyBoy

[rudds1]

The amount of people getting flashed on m1 early hours of this morning was unbelievable ,mind you m25 was getting a fair few as well

 

---------- Post added 06-02-2018 at 11:48 ----------

 

so how do the cameras work then? are they some kind of average speed camera

 

There is a wire loop in each lane that detects speed of vehicle

[DT Ralge]

The amount of people getting flashed on m1 early hours of this morning was unbelievable ,mind you m25 was getting a fair few as well

 

---------- Post added 06-02-2018 at 11:48 ----------

 

 

There is a wire loop in each lane that detects speed of vehicle

 

The wires in the road surface (MIDAS - motorway incident detection automatic signalling) has no speed enforcement role/function - no individual car can be identified by MIDAS.

MIDAS picks up slowing, bunching traffic and prevailing speed and will automatically offer a lower advised speed limit on the matrix signs some distance before the congestion/hold-up. The same technology is present on slip roads that generates messages like (queue on slip road) - although, equally, these messages can be posted by Highways England personnel with “eyes on” (in person or by CCTV).

Conversely, a vehicle may be stranded, cause HE to enforce a lower speed limit. Even so, the stranded vehicle may then be moved, HE remove the enforced lower limit but the algorithm that MIDAS generates retains the lower speed limit until the traffic starts moving more freely, at high speed and less densely.

Edited February 7, 2018 by DT Ralge

[geared]

HE remove the enforced lower limit but the algorithm that MIDAS generates retains the lower speed limit until the traffic starts moving more freely, at high speed and less densely.

 

Which can take longer to clear as everyone is still being forced to do 40mph on a clear stretch of motorway :hihi: