Road records

Busiest non-motorway road

The A3 Kingston by-pass between Tolworth and New Malden, which carries 125000 vehicles per day.

Busiest motorway

The M25 between junctions 15 and 14 (that's the M4 to A3113: I blame the airport) carries 165000 vehicles per day.

Worst junction to miss

Junction 10 of the M11, travelling south: the next exit is junction 8, 17.75 miles south.

Steve Barnard asks: what about missing M26 J2a Westbound? According to my road atlas, it's 9 miles to the next junction (M25 J5), but you can't leave there, and it's another 10 to M25 J6. I know as you pass J2a Westbound on M26 there's a sign warning of ``no exit for x miles'', but I can't remember what distance is quoted. I think it's 18 miles (which is within the tolerance of the rounding errors of the quoted junction spacings on the road atlas), but if that's right, it beats the M11. I feel a ``measuring across maps spread out on the floor with a bit of string'' moment coming on.

Simon Frampton adds: Mr. Barnard would be right. If you miss J2a Westbound on the M26 you cannot leave the motorway until you reach Junction 6 of the M25 at Godstone. There is a signpost on the M26 stating the distance to the next junction as being 18 miles away, but I think I've actually clocked the distance as being closer to 18.5 miles. The reason for this problem is because the M26/M25 interchange at J5 of the M25 is restricted. The M25, M26 and A21 all meet here, but you cannot access the A21 from the M26 westbound or access the M26 from the A21 in either direction. The M26 simply allows westbound traffic to flow from the M26 to the M25. If you're on the M25 headed anti-clockwise (the same direction as if you'd come up the M26) you cannot join the M26, but can head south on the A21.

Shortest gap between motorway exits

The distance between junctions 19 and 18 on the M8 in Glasgow is less than 160 metres (643 feet). In fact, that whole section of the M8 is riddled with junctions, many of them with restrictions.

Worst traffic jam

On the 5th of April, 1985, there was a 40 mile jam on the M1 between junctions 16 and 18.

Longest line of stationary traffic

On the 17th of August, 1988, there was 22 miles of stationary traffic between junctions 9 and 8 of the M25.

Worst UK traffic jam

(No, I don't know why this is different from worst traffic jam above!)

The joint worst UK traffic jam is one on the M6 between Charnock Richard and Carnforth, Lancs, on 17 April 1987, and involved around 200000 people and 50000 vehicles.

Most carriageway lanes

There are 17 carriageway lanes side-by-side on the M61 at Linnyshaw Moss, Worsley, Greater Manchester.

Longest ring road

The longest ring road in the world is the M25 London Orbital Motorway. It is 195.5 km (121.5 miles) long. Constructed from 1972 to 1986, it cost an estimated 909 million pounds (7.5 million pounds per mile).

Busiest road

The busiest road in the world is Interstate 405 (the San Diego Freeway) in Orange County, California, USA. It has a peak-hour volume of 25500 vehicles on a 1.5km (0.9 miles) stretch between Garden Grove Freeway and Seal Beach Boulevard.

Longest traffic jam

The longest traffic jam in the world on record extended 176 km (109 miles) from Lyon towards Paris, France on 16 February 1980.

Worst UK road accident

The worst road accident in the UK was a coach crash near Grassington, N Yorks, on 27 May 1975, in which 33 people died.

Most complicated British interchange

The most complicated British interchange is situated at Gravelly Hill north of Birmingham, on the Midland Link Motorway section of the M6. Popularly known as Spaghetti Junction, it has 18 routes on 6 levels, together with a diverted canal and river. It consists of 26000 tonnes of steel, 250000 tonnes of concrete and 300000 tonnes of earth, and cost 8.2 million pounds to construct.

Shortest street

The world's shortest street is Elgin Street in Bacup, Lancs, UK, which is only 5.2 m (17ft) in length. Trianglen, a designated road with buildings on only one side, at Store Heddinge, Denmark, is only 1.85m (6ft 1in) long. It forms one side of a road junction.

James Cloninger adds: I think perhaps you should add one more reference to your designation of ``shortest street'': that of McKinley Street, in Belfontaine, Ohio in the US, which is 31 feet, but unlike Elgin St, is drivable. It has one building (a hardware store) on the north side, bordered by a railway on the south side, and two roads (Garfield Ave and ColumbusAve) on the other two sides which eventually merge about 100 feet on the other side of the rails.

Steepest British road

The steepest motorable road in the British Isles is the unclassified Chimney Bank at Rosedale Abbey, N Yorks, which is signposted ``1 in 3''. The county surveyor states that it is ``not quite'' a 33% gradient.

An unclassified road at Ffordd Penllech, Harlech, UK, officially described as not suitable for motor vehicles, is 1 in 2.91 at its steepest point.

Steve Barnard adds: Incidentally, the steep road in Harlech has a standard gradient sign at the top saying one in two and a half. Having walked up it quite recently, I'd debate the quoted 1:2.91 - it's steeper than that. It's worth noting that for railways a gradient quoted as one in 50 has a sine of 1/50, whereas road gradients are quoted as the tangent - so a 1 in 50 on a road isn't quite as steep as a 1 in 50 on a railway. At shallow grades it doesn't make a lot of difference, but if the 1:2.91 is measured ``railway-wise'' (the easiest way to do it on the ground), then it's tan(arcsin(1/2.91))=1/2.73 ``roadwise.''

Highest UK roads

The highest unclassified road in the UK is a private lane leading to the summit of Great Dun Fell, Cumbria, which reaches an altitude of 847m (2780 ft). The road leads to a MOD and Air Traffic Control installation, and a permit is required to use it.

The highest classified road in the UK is the A93 over the Grampians, which reaches an altitude of 665m (2182ft) at the Cairnwell Pass.

Lowest UK road

The lowest surface road in the UK is north-east of Holme, Cambs. It is 1.62 m (5ft 4in) below sea level.

Largest parking areas

The largest parking areas in the world (excluding the M25) are at the West Edmonton Mall, Alberta, Canada, and at the National Exhibition Centre, Birmingham, W. Midlands, UK, which can both hold 20000 vehicles.

Longest UK road

The longest designated road in the UK is the 648 km long (403 mile) A1 from London to Edinburgh.