The following list represents perhaps a slightly controversial view of the various "firsts". For this reason, a "confidence" column is included, and where this is less than 100%, then an alternative view may well be possible, and should be passed to the webmaster for consideration. Clicking on the scheme name will bring up a map or picture of the relevant section of the scheme (where available). Click on the browser's "back" button to return to this page.

At 231 miles (370km), the M6 is the UK's longest motorway and extends from Catthorpe (junction 19 on the M1) to the Scottish Border (Guards Mill) where it becomes the A74(M) which itself joins the M74 to Glasgow. Taken together with the A74(M) and M74 (which is itself being extended by 5 miles) the total continuous length of motorway will be about 370 miles. It is very unlikely that the sections in Scotland will be renumbered.

The first section was opened in December 1958 (Preston By-pass) and the last exactly 50 years later in December 2008 (Carlisle to Guards Mill). It is generally dual three-lane carriageways, with short sections of dual four-lane between the M56 and M62 and between the M61 and M55. The section North of Birmingham is so seriously congested, that a new motorway, the M6 Toll, Birmingham Northern Relief Road opened in December 2003 to provide an alternative route.

The Highways Agency website suggests that the M1 is the longest motorway, but since it is about 41 miles shorter than the M6, this must be an error. Even when work on upgrading the A1 to motorway standard is complete, the total continuous length of motorway will only be some 215 miles.

There are a number of motorways which are 1 mile (1.6 km) or less in length. There have been conflicting claims on this subject, but it now appears that the A635(M), which is joined to the A57(M), Mancunian Way, is the shortest at about 300 metres long.

There are sections of motorway where local widening occurs to accommodate slip roads, and at these points, the motorways could well be five or even six lanes wide. However, the foreshore section of the M2 in Belfast, opened in 1973, has a long section which is dual 5 lanes wide. More recently, opening in December 2005, the M25, between junctions 12 and 14, was widened to dual 5-lanes and the section between junctions 14 and 15 to dual 6-lanes. 

The A601(M), a 500m long connection between junction 35 on the M6, and the B6254 near Over Kellet (The "Carnforth Quarry Link Road") consists only of a single 7.3m carriageway and two 1m wide strips. Its overall width is about 50 feet (15m). The background to this road is described on "The Lancaster by-pass section of M6 and the Carnforth link roads A601(M)" page. The M6 originally terminated on the A6 north of Carnforth. When it was extended northwards, the link through to the A6, which was of course built to motorway standard, was effectively "cut off", and this was redesignated the A601(M). The roundabout which connected the two motorways was automatically a "special road" by virtue of the fact that only motorway traffic could get to it. When the "Quarry link" was added, this provided a direct connection to a motorway, and in order to prohibit non-motorway traffic from using it, it had to be designated as a motorway itself. It therefore also became the A601(M). The route numbering is illogical, because the A601 is, in fact, the Derby Ring Road.

The M62 is the highest motorway in the UK, reaching 1,220 feet (372m) AOD near to the boundary between Lancashire and Yorkshire close to the Pennine Way footbridge. The M6, passing over Shap, in Cumbria, reaches 1,040 feet (317m) AOD and is probably the second highest motorway, although the M74 at Beattock is thought to be at a very similar height. (AOD="Above Ordnance Datum", ostensibly sea-level).

The Alconbury to Peterborough section of A1(M) runs generally on the line of the old Ermine Street Roman Road, and is therefore "straight" for a considerable part of its length. Between Alconbury and Stilton, it is more or less straight for a distance of nearly 7 miles. Minor deviations have, however, been necessary near to Sawtry and Connington to accommodate junctions and side road diversions.

Probably the longest individual section of straight motorway occurs on the A1(M) Durham Motorway, near Newton Aycliffe. The motorway immediately south of Bradbury (Junction 60) includes a 3½-mile straight section.

Design standards for motorways (and their intersections) require that gradients should be no steeper than 4% (1 in 25) except that in exceptional circumstances, gradients of 5% may be used over short lengths. Between the Shore Road and Sandyknowes section of the M2 in Northern Ireland, the gradient reputedly reaches 1 in 19½ (5.13%) in places. Shortly before the contract was let it was decided that a crawler lane should be added on this outward carriageway.

Steep gradients are often found on complex interchanges, but where the M90 terminates at the Craigend interchange with the southern by-pass to Perth, the topography dictates gradients said to be well above the recommended maxima. The actual gradients achieved are not yet known.

The longest section of motorway between junctions occurs on the M11. The distance between junction 8 and junction 9 is 15.2 miles (24.3 km). However, junction 9 only has northbound slip roads, and in a southbound direction, there is an interrupted length of 17 miles (27.1 km) between junction 10 and junction 8.

The first to be opened was the Watford Gap Service area on the same day as the M1 - 2nd November 1959. It was operated by Blue Boar, but did not offer full catering facilities until September 1960.

The second M1 Service area, at Newport Pagnell, opened in August 1960 and was operated by Motorway Services Ltd.

In 1963, a further five Service areas were opened, Keele, Charnock Richard and Knutsford (all on the M6), Farthing Corner (M2) and Strensham (M5)