Would this trigger an average speed check?

[HenryHippo]

I join the M4 at Junction 6, and exit a few miles later at Junction 7. I only pass 1 yellow average speed check gantry (50 mph limit).

Because I only pass 1 camera, it is not possible for it to capture my average speed on this pass? Or are there cameras at entrances and exits to the motorway also?

[The spinner of plates]

Don’t know that stretch, but you need two known reference points to capture the average.

[PDP76]

Doubtful.
My girlfriend lives in Nottingham which is festooned with average cameras.
Many people pass one above limits one the roads covered , including myself now if you are going to be turning off before you get to the next camera.
If not then steady as she goes.

[Panamax]

HenryHippo said:

I join the M4 at Junction 6, and exit a few miles later at Junction 7. I only pass 1 yellow average speed check gantry (50 mph limit).

I think you've missed the camera at the very bottom of the slip road as you leave the roundabout to join M4 at J6.And there's a third one on the exit sliproad at J7.

[OutInTheShed]

Generally, the exits and entrances are covered, but the cameras may not be so obvious. Can be hidden by bridges and signs etc.
Can be blocked as well as hidden, by lorries in the inside lane of the slip road etc.
Not saying there is always 100% coverage.

[J__Wood]

Panamax said:

HenryHippo said:

I join the M4 at Junction 6, and exit a few miles later at Junction 7. I only pass 1 yellow average speed check gantry (50 mph limit).

I think you've missed the camera at the very bottom of the slip road as you leave the roundabout to join M4 at J6.And there's a third one on the exit sliproad at J7.

Yep three, so unless OP is really lucky and two aren't working or driving at <= 56 mph...

[HenryHippo]

Hmm, I'll take a look and see if there are cameras at the start of the slip roads too then... was just a thought that came into my head as I realised I only passed one whilst on the main motorway before exiting