The M4 Motorway (Heathrow Airport Spur Road) (Bus Lane) Regulations 1997
These Regulations provide that motor vehicles (other than buses, emergency vehicles and other specified classes of traffic) are prohibited from entering or proceeding in the bus lane of the southbound carriageway of the M4 Heathrow Airport Spur Road, which leads from the M4 Motorway to Heathrow Airport.