BMW R1200RT/R1250RT Forum

Has anyone got a definitive answer on these (polite responses only please  ). if you are in a average speed controlled zone and you stop for a break - when you exit the zone - how is the average calculated. UK & EU.

Mike, where they are in force (motorways), I don't think there are places to stop for a break, unless you break down.

Lots of A Roads close to me have them 

As the name implies it's your average speed between them.  So on a section 1  mile long you could do 90 mph for 1/2 a mile then 45 mph for the next half a mile and you would be recorded as doing 67mph, I think.  Too cold here to be sure.

They work by using an automatic number plate recognition (ANPR) system to record a vehicle's front number plate at each fixed site. As the distance is known between these sites, the average speed can be calculated by dividing this by the time taken to travel between two points.

Interesting bit is front number plate, how does that work on a bike then?

RTman10 wrote: As the name implies it's your average speed between them.  So on a section 1  mile long you could do 90 mph for 1/2 a mile then 45 mph for the next half a mile and you would be recorded as doing 67mph, I think.  Too cold here to be sure.

This is the grey bit. I've been told some systems use GPS. So if you speed then break then speed again to get a reading below average they only record motion.

As RT man says it just times the journey between the two points, GPS is receive only technology. There are varios urban myths about changing lanes and I'm not sure what the current rules are on that.

Like all front facing systems they don't work on  bikes, but.  The A9 has them for over 100 miles and on each pylon on single carriageway bits they point both ways.  I've never been brave enough to test them.

If they're front facing, I'll set the cruise control to 10% over in the car, 20% over on the bike.

If rear facing, it's 10% over for both.

Speeds taken from speedo on car and satnav on bike. 

I bought a Volkswagen with an expensive satnav to eliminate having to stick anything on the windscreen, only to discover that it doesn't show speed limits, current speed or "safety" cameras !. Never again  - if there's another new car it will be back to looking for a way to use the Navigator V in the car !

Casbar wrote: They work by using an automatic number plate recognition (ANPR) system to record a vehicle's front number plate at each fixed site. As the distance is known between these sites, the average speed can be calculated by dividing this by the time taken to travel between two points.
Interesting bit is front number plate, how does that work on a bike then?

Have I missed something here?  I'm sure that I've seen average speed cameras that look at the rear of the vehicle.  From memory they were up around Notts or somewhere that way.  Agreed they only used to look at the front, but that wasn't going to last was it

Permanent ones on motorways are normally mounted on the back of overhead gantries and read your back plate.  In roadworks and on single carriageway roads they are normally forward facing.

I'm sure everybody already knows that they also use the same system in France between Péage's

You say that but I have never known anybody to get had for checking out on the peage  and being fined for getting there faster than the speed allows.
I'm so sure of this I always pull in to a rest area somewhere between them for a quick rest just to make sure.

gents, i think you will find they will look at both from and rear when they can afford the cameras to do it. You see people were getting away with it by having different numbers on the front than the back. Well at least drivers of a certain age and sex were in their certain cars.


in the average zone you will often find more than one set of cameras again for the reasons mentioned in other posts

stayingupright wrote: I'm sure everybody already knows that they also use the same system in France between Péage's

Wow never even thought of that one. Never been challenged and have been guilty on several occasions. :not speak: