Motorway driving is one of the safest forms of driving, as long as motorway lane rules are adhered to. The speeds may be about twice as high as on B roads, but the number of lanes and the mixture of speeds means there is usually plenty of space to operate. The more lanes a motorway has, the safer it is because each vehicle type and driving style is catered for.
The first lane is widely accepted to be the slowest lane, and the lane nearest to the central reservation should only be used for overtaking. In between there is usually either one or two middle lanes which can be used according to the conditions of the day.
Using good lane discipline, each lane should be travelling faster than the one to the left, but in some cases the road conditions can warrant a temporary change in lane layout.
One of the biggest causes of congestion on motorways can be poor observation of motorway lane rules. If a motorist enters a faster lane but does not return to the original lane after overtaking, this can cause a ripple. When other drivers are behind a vehicle travelling at the same speed as the slow lane, it means they have to overtake using a faster lane. This effectively turns a 3-lane motorway into a dual carriageway, because the first two lanes become slow lanes.
More vehicles filtering into the fast lane(s) means the flow of traffic reduces speed, and therefore a large number of vehicles have to suddenly apply the brakes when they reach this situation. This then creates what is known as a ‘phantom’ traffic jam. Each subsequent braking vehicle brakes slightly harder than the last one as they are reacting to the sudden brake lights rather than the incremental slowing of traffic.
A common sight on Britain’s motorways these days is HGVs that are equipped with limiters which prevent the vehicle from exceeding a given speed rate. This is good for fuel economy and safety, but it can mean that overtaking takes several minutes. When one vehicle travelling at 59mph is overtaken by another at 60mph, it takes those two lanes out of service for the rest of the motorway users.
And let’s not get started on those who just stay in the middle lane(s) for the whole journey whilst a queue forms behind them…