Heathrow speed cameras.....for info

[madcjd]

Just in case anyone is planning on driving to Heathrow.....
As of 1st May ANPR has been installed and active all round the perimeter road.
It's a series of matrix signs displaying your speed, followed by the actual 'camera' which is yellow in colour and quite small in size, but clearly visible.
For most parts it's 30 MPH around the perimeter road, but, goes up to 40 in certain areas (between Hatton Cross and T4).
It's claimed the cameras are predominantly for security issues, but, they also happen to record speed. No doubt these things will generate lots of cash.
Just thought I'd throw this one out there as I work at LHR and regularly use various sections of the 'perry track'.