Local Variations

Occasionally anomalous cultures develop at local roundabouts. For example, I can think of a roundabout in my local area where it would be hazardous to go ahead in the left lane. This is because drivers have learned to turn left from the middle lane!! (The highways agency may eventually get around to updating the signage.) Why would this happen?

Well, if the main flow of traffic always goes left, and if that traffic is often congested, then rather than create a huge single file queue in the left lane, drivers use the centre lane and create a shorter, double file queue. When the traffic eventually begins to move, what remains are two lanes of traffic, both turning left.

If the first exit of a roundabout goes to the Blackwall tunnel (major arterial route, and only way of getting across the river in the area), and the 2nd and 3rd exits of the roundabout are both dead-end industrial estates, then you could predict that most of the traffic will be turning left. Therefore, use the right hand lane for the other exits.

If the second exit of the roundabout leads only to a Concert Arena, then you may predict that at the weekend, and possibly in the evening, it will carry more traffic on that exit than in the early morning rush hour!

Learn to use your detective skills. The best drivers can accurately predict the behaviour of other vehicles by assessing ALL the information at their disposal. Your ability to stay safe lies mainly in your own hands.

You may learn to distrust other drivers, and not to assume that they will follow an officially prescribed path through the hazard. Such scepticism (or paranoia) is called "defensive driving".

Defensive Driving

This illustrates a common problem at roundabouts. The driver on the red route is lost, and turns unexpectedly across the path of the other driver at the last second. It is the job of the driver on the green route to drive defensively, to predict this behaviour, leave enough space, and turn safely.

Good drivers are rarely taken by surprise. In fact, experienced motorists may be taken more by surprise by considerate driving than by inconsiderate driving!