M25 motorway "Inside the M25" and "outside/beyond the M25" are colloquial, looser alternatives to "Greater London" sometimes used in haulage. The Communications Act 2003 explicitly uses the M25 as the boundary in requiring a proportion of television programmes to be made outside the London area. Two motorway service areas are on the M25, and two others are directly accessible from it. Those on the M25 are Clacket Lane between junctions 5 and 6 (in the south-east) and Cobham between junctions 9 and 10 (in the south-west). Those directly accessible from it are South Mimms off junction 23 (to the north of London)
West London Orbital sections: The Dudding Hill Line, the North London Line and the Hounslow Loop. The Dudding Hill line itself has had no scheduled passenger service for over a century. It has no stations, no electrification and a 30 miles per hour (48 km/h) speed limit with semaphore signalling, and is lightly used by freight and very occasional passenger charter trains. It is roughly 4 miles (6.4 km) long. Near the site of Old Oak Common the West London Orbital would connect to the existing North London Line, and then further south at Acton, use the link down to the Hounslow Loop