Canberra 97
The plan is for the main M25 four carriageways north & south are to go into a tunnel. The slip roads to accessing and leaving the M4 will have to be re-aligned. When northbound traffic leaves the tunnel the incline will increase from below current ground level therefore increasing the climb to clear the M4. Any HGV's grinding to a halt in a traffic holdup will slow the flow, as occurs now. The two standard diversion routes A4 and A3044 will be altered to accommodate the extended Terminal 5 which goes west towards the M25.
All described in the photo montage supplied by LHR, but the above is not being paid for by LHR, neither the impact of removing all the spoil by road.
