It's already happened in Kent and has been likewise on M42 for atvleast a couple of years, has improved traffic flow considerably in both cases and I'm sure we would have heard if there had been a disaster. There are emrgency refuge areas and the sections of motorway are permantly monitored by cctv and all have overhead gantry lane control too.
Hum..shows what I know about motorways,
Use M1 occasionally to Luton Airport, M25 sometimes to Stansted Airport & M4 to London Airport.
I know everything about the North Circular though..!!
I'd settle for that little Motorway use!!
or North Circular, A13, M25, A20 Brands Hatch,