The Road From Hell

Last week I had the utter misfortune to work in Hampshire for the week. I’m sure it is a lovely place really but all I saw of it was the inside of a high tech datacentre, surrounded by razor-wire and with the sort of high tech security gubbins that would give a Bond villain a wet dream. Well, it would have done if any of it actually worked in the appropriate manner but mostly it just served to lock people in or out of wherever they didn’t want to be. At one point I even had to rescue a somewhat pissed-off dwarf that was trapped inside a security cubicle.

Anyway, aside from the horrible working environment I also had a long and mercilessly tedious drive from Scotland to the South of England and back. According to the route planner this should have been straight forward enough and, travelling down, it was. On the way back it should have been a case of sticking on the Rammstein albums, aiming the car Northwards and trundling up the motorway for just over six hours. However, it is never that easy as I discovered when I came across the misery that is the M6 between Birmingham and Manchester. It is a journey that should have taken about an hour. In fact it took over four.

The odd thing is that I had already had to drive through various roadworks which one would have thought would cause some traffic congestion, but on the stretches of road where the traffic kept grinding to a halt there was nothing obvious that had caused it: no road works, no accidents, no breakdowns or other blockages. This is actually a well-known phenomenon: the phantom traffic jam. These are caused when vehicles are travelling too close together and something causes one car to brake (for example, an inconsiderate lane change). This may only be a very slight change of speed but the effect is that the vehicle behind must brake at least as hard and the vehicle behind them at least as hard again. The end result is that the vehicles at the end of the line of too-close vehicles brake to a standstill and the phantom traffic jam snakes its way down the motorway until the number of cars leaving the stoppage exceeds the number of new cars arriving. Last Friday, this was in Birmingham.

There have been various attempts to try to stop these phantoms occurring: variable speed limits, chevrons on the road or traffic lights to restrict the number of vehicles that can join the motorway. Around Birmingham they have even pressed the hard shoulder into use as an extra lane thus downgrading the motorway into a particularly wide dual-carriageway. Presumably, these schemes have had some effect but they don’t appear to be effective enough. This is not surprising as the motorway system around Birmingham was designed for traffic levels in the 1960s and precious little has been done to improve the situation (aside from the comically ill-conceived toll road which sits as a folly to the idea of privately run infrastructure).

What I am wondering is whether the real answer is staring road planners in the face. I had to drive through a few roadworks which had a reduced number of narrowed lanes. In all these places the traffic was dense but free flowing. What appeared to make the difference was that they had 50 mph speed limits enforced by average speed cameras. The traffic, whether restricted HGVs or over-powered executive cars, all travelled at a steady 50 mph. They didn’t (for the most part) change lane and didn’t attempt to exceed the limits for fear of incurring the wrath of the digital average speed cameras. I’m probably like everyone else in that I dislike these things as they follow the counter-intuitive “less haste, more speed” mantra but it could have saved 3 hours off my journey last week. If that is what it takes to make the road system work then it must be worth considering.