Andy Brice

The Dangers of Traffic Turning Left

In the past weeks there has been a surge in news coverage about cyclists killed on Britain’s (and particularly London’s) roads.

I think this is a problem that needs talking about, not because I’m some sort of cycling zealot (cars, vans & trucks are a very practical form of transport in many scenarios). But firstly because people are dying, and secondly because perceived danger on roads is one of the key factors dissuading people from cycling. And making it easier to travel by bicycle is looking like the only viable solution to many problems facing urban areas. (Specifically traffic congestion and air pollution.)

Turning Left: The Highway Code is Broken

A large number of these accidents occur when a vehicle (especially a HGV) makes a left-hand turn, colliding with a cyclist in their blind-spot. Some of these incidents have received high-profile news coverage. And yet I’m bewildered that no one seems to be talking about one of the root causes of this danger; which is that the rules of the road never clearly specify who should give way in this situation!

Diagram showing potential collision between a bicycle and a car ahead as the car turns left

When I’m cycling, is it ever okay to undertake a vehicle that is indicating left?

When I’m driving, is it ever okay to cause a cyclist to stop by turning left across their path?

Do the answers to these questions depend on the lane markings?

No one seems to know. And The Highway Code is vague and ambiguous. [1] When two road users are on a collision course, with poor visibility, both reasonably believing they have priority, accidents are tragically inevitable.

My Proposed Solution

Where there is a demarcated cycle lane, it should have priority over turning traffic:

Diagram showing a car giving way to a cycle lanes as it turns left across it

Again, not because I’m being a cycling zealot, simply because traffic manoeuvring across lanes has to give way to the traffic in them, that’s just how roads work. So before turning left, a driver should have to wait for cyclists to pass, or merge into the cycle lane ahead of the junction.

Where cyclists are lane-sharing however, a cyclist should not be allowed to undertake a vehicle that’s entirely ahead of them, if it is indicating left:

Diagram showing a bicycle giving way to a car ahead that is indicating left

This way, a driver can check their blind spot once, then turn left, confident that their path is clear.

There are of course some complications, such as how this would relate to the legal status of advisory cycle lanes, and filtering through stationary traffic. Much of The Highway Code pertaining to cyclists undertaking is dangerously vague and ought to be clarified. And with the frequency at which people are being killed in road accidents, I don’t think it’s hyperbole to say this needs addressing with some urgency.

[1] Rule 72 says DO NOT ride on the inside of vehicles signalling or slowing down to turn left. This implies that drivers have priority, because cyclists are not allowed to undertake them when they’re turning left…

But then Rule 167 says DO NOT overtake where you might come into conflict with other road users. For example approaching or at a road junction…Stay behind if you are following a cyclist approaching a roundabout or junction, and you intend to turn left. This seems to contradict Rule 72 and implies cyclists have priority, because drivers are not allowed to overtake them before turning left.

The code is unclear as to whether a cyclist is permitted to undertake a vehicle that’s ahead and to their right, if it abruptly slows down to turn left. Or whether the rules for overtaking also apply to lane-sharing where cycles are just naturally travelling slower. Or indeed how any of this is affected by the presence of a compulsory or advisory cycle lane.

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