How much room does a driver give a cyclist when overtaking? What do you do as a cyclist when a car is passing you? How straight is the line you ride as vehicles pass you by? A group of scientists in Taiwan built a special bike to answer these questions and more.
It was instrumented to record lateral distance from the passing motorists, wheel angle and speed control. That’s a lot of special kit to add to a bicycle on city streets. It includes an ultrasonic sensor, camera, a variable resistor in the headset and a solid state compass, gyroscope and accelerometer. OK, it costs less than a CF disc wheel but it’s a lot of value to expose to potentially hazardous situations.
Well, as with the vast majority of urban rides, nothing went wrong and the data were analysed. Thirty-four riders were overtaken a total of 1,380 times. The equipment revealed that
• motorbikes passed more closely to the bicycle than cars and trucks did.
• cyclists couldn’t keep such a straight line when buses overtook
• vehicles passing slowly led to more cautious but less stable riding
The use of a quasi-naturalistic riding method to investigate bicyclists’ behaviors when motorists pass, published in Accident Analysis & Prevention, available online 29 March 2013, by Kai-Hsiang Chuang, Chun-Chia Hsu, Ching-Huei Lai, Ji-Liang Doon and Ming-Chang Jeng