SAFETY ISSUES WHEN DRIVERS OVERTAKE BICYCLISTS: OVERTAKING PROXIMITIES, VEHICLE TYPE, HELMET USE, AND BICYCLIST'S DISTANCE-TO-KERB

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Most of the journeys people make are less than 2 or 3 miles long. These would usually be fastest by bicycle, but people drive more often than not. People are missing an opportunity for valuable exercise, are causing tremendous amounts of unnecessary pollution in our towns and cities, and are killing one another in collisions. People don't cycle more because they're scared of being hit by a car. At least 100 cyclists die from being hit by cars each year in the UK and over 2,000 are seriously injured. The research proposed here aims to make it less likely that cyclists have such accidents, which will encourage more people to cycle. Collisions between cars and bicycles tend to happen at road junctions. However, collisions also happen when cars overtake and when this happens it is serious, because being hit by an overtaking car is one of the worst things that can happen to a cyclist. If we understood what determines how close drivers get to the cyclists as they overtake, we could do something to make collisions less likely, either in the way we construct our roads or, more likely, with advice to cyclists about how they should ride. There are currently three big ideas about what determines drivers' overtaking closeness, and we plan to test them all. The first idea is that the distance a driver leaves when overtaking a cyclist is related to the distance the cyclist left between themselves and the edge of the road. In other words, many cyclists are convinced that if they ride away from the edge of the road, drivers will leave more space as they overtake, making the cyclist safer. We know that a lot of cyclists rely on this idea for their safety, but it has never been properly tested and all we have are lots of unscientific reports based on people's experiences. The idea urgently needs testing properly.We plan to do this by fitting a bicycle with a distance sensor feeding into a computer. This will record how far away each vehicle is as it passes the bicycle. The computer will also get information from a video camera (so we can later see what the overtaking vehicles were) and a microphone, so the cyclist can record any other useful information about what is happening as people overtake. By riding the bicycle along a series of roads we can directly test the idea that the distance to the bicycle's left affects the space drivers leave as they overtake. We can also see whether the really important thing is not the space to the cyclist's left but perhaps how wide the road or the lane is. This instrumented bicycle also allows us to test the other two ideas we are interested in. The first of these is that some vehicles-particularly buses-will overtake cyclists in a more risky way than others. We suspect this because we recently did a survey of almost 5,000 cyclists and asked them about any accidents they had had. We found that accidents involving buses stood out from other collisions, as they almost all happened as the bus overtook. We are therefore very keen to see whether bus overtaking is notably different in this study.The final thing we wish to do is to have the rider wear a cycle helmet for half the time and no helmet for half the time. A lot of experienced riders report that drivers are more careless around a cyclist if the cyclist is wearing a helmet. If this is true, it would suggest that wearing a helmet might actually have the opposite effect to that intended, and put the wearer in greater danger. It will therefore be of great interest to see whether drivers tend to overtake closer when the cyclist is helmeted than when he has no helmet. The findings from this study will be widely distributed to interested parties. The results, whatever they prove to be, will be very valuable for guiding road safety activity. We will therefore inform local and national government and other road safety groups (e.g., BRAKE, RoSPA) and groups interested in cyclist safety (CTC, LCC, etc.).