TY - JOUR PY - 2021// TI - Risk to bicyclists in a separated path from left turns across multiple lanes: a case for protected-only left turns JO - Transportation research record A1 - Saeidi Razavi, Ray A1 - Furth, Peter G. SP - 174 EP - 183 VL - 2675 IS - 10 N2 - At signalized intersections, permitted left turns (i.e., on a green ball, after yielding) across multiple through lanes and across a separated bike lane or bike path present a threat to bicyclist safety. A conflict study of two such intersections with a bidirectional bike path found that when cyclists cross while a vehicle is ready to turn left and there is no opposing through traffic to block it, the chance of the left-turning motorist yielding safely was only 9%, and the chance of their yielding at all--including yielding only after beginning the turn, then stopping in the opposing through lanes--was still only 37%. Motorist non-yielding rates were worse toward bikes arriving during green, toward bikes approaching from the opposite direction (i.e., riding on the right side of the road), and toward bikes facing a queue with multiple left turning vehicles. Of 112 cyclists who arrived on green when there was at least one left-turning car, but no opposing through traffic blocking it, 73 had to slow or stop to avoid a collision. Although these conflicts could be essentially eliminated using protected-only left turn phasing (turn on green arrow), common existing criteria prefer permitted left turns to reduce vehicular delay. A case study shows how, by considering multiple signalization alternatives, it can be possible to convert left turns to protected-only phasing without imposing a substantial delay burden on vehicles or other road users.

Language: en

LA - en SN - 0361-1981 UR - http://dx.doi.org/10.1177/03611981211010789 ID - ref1 ER -