When it was first opened some two decades ago, the M25 orbital motorway was hailed as the answer to London’s traffic problems. It meant that people driving from one side of London to the other would no longer have to drive through the tangle of shops, streets, people and other vehicles of London itself. But of course it was not long, because this always happens, before the M25 itself became too popular for its own good. By the mid 1990s, drivers using it could expect to spend much of their time crawling along it and tailbacks of several miles were common. It is said to have inspired the title track of guitarist Chris Rea’s album Road to Hell, and in his book, co-written with Niall Gorman, the humorous writer Terry Pratchett uses it as a symbol of evil.

Various solutions have been mooted. One is to build another motorway that orbits the orbital. Another is to widen the existing motorway. However, it would be far too expensive to widen the whole 117 miles of it. So which bits should it be? Well, of course traffic experts can study traffic volume and calculate which bits need the most relieving. But that is only a mechanical aspect. There is also the human aspect. Which bits of the motorway cause drivers the most stress? In order to find this out, a team of six researchers have recently been undertaking a noble task. This was to drive around the M25 up to five times a day while strapped up to all kinds of wires which monitor heart rate and blood pressure. Meanwhile, a co-worker in the back seat noted down what was happening where. Initial results indicate that the Dartford Crossing at the eastern extremity of the M25 causes the most stress as drivers worry about the eight lanes on each side of the toll booths, which lane would be quickest to get into and whether they have the right change. Another finding is that in general driving anti-clockwise round the M25 is notably more stressful than doing it clockwise. It is speculated that this is because most drivers prefer turning the steering wheel to the left and/or the fact that Britain drives on the left, so it seems more ‘natural’ to them.

to crawl along: voortkruipen.

lane: vak.

to moot: discussiëren.

to orbit: doorlopen rond.

to relieve: ontlasten.

to strap up: met pleisters vastmaken.

tailback: file.

tangle: wirwar.

booth: hokje.