Originally Posted by
Gonzo
I’ve worked at LHR for 20yrs, and I agree with Prophead. The majority of cars on the M25/M4 do not go to/from LHR.
The original point was whether LHR was the primary cause of traffic in and around the M4/M25 interchange. That's not the same thing as journeys to/from LHR, which is what I understand you and Prophead assert. Journeys to/from LHR are likely to be a major part of the wider picture, but there will also be journeys in and around LHR caused by businesses, families and individuals who have located in the area because of its proximity to LHR.
The fundamental point remains that additional journeys on this busy section of the road/motorway network, caused by an expanded LHR, results in a requirement for expensive construction of additional road capacity.