It will prevent the rolling roadblock effect of lorries overtaking each other over long distances whilst travelling at 56 MPH against their speed limiters. Motorway road capacity will be increased at low cost. Accident rates will be reduced because faster vehicles will not have to change lanes so often in order to pass Lorries in the third lane.
A lorry may not overtake another vehicle on the Motorway unless it is travelling at under 55 MPH. An overtaking lorry must fall back if it is unable to sucessfulyy overtake within two minutes.
An alterantive would be ban all Lorry overtaking abouve 50 MPH except in new "Overtaking Allowed" sections (on hills).