Developing Bicycle Equivalents for Mopeds in Shanghai, China

Abstract

The bicycle equivalent (BE) of the moped is a key nonmotorized traffic flow parameter when bicycles and mopeds share the same lanes. However, this parameter should not be considered a constant, because it may be affected by factors such as the mixed proportion of the nonmotorized traffic flow. This study estimated the effects of traffic flow characteristics and road design parameters on the BE. Basic traffic flow parameters (i.e., flow, density, and speed) were extracted from video data collected at three observation sites in Shanghai, China. A concept method was used to calculate the BE of mopeds in terms of their time–space resource occupancy on traffic facilities. The free-flow speed characteristics of bicycles and mopeds were investigated, and relationships between speeds and densities in the mixed traffic flow were analyzed. The BEs were estimated for a range of characteristics related to traffic condition or road design (i.e., moped percentage, traffic flow density, width of nonmotorized traffic lanes, and nonmotorized traffic lane grades). The effects of these characteristics on the BE and the variation trends of the BE were observed, and reasons for these trends are discussed. The study findings provide valuable support for the measurement of nonmotorized traffic mixed with mopeds and bicycles in different traffic and road design conditions and could support future studies for capacity and level of service of dedicated nonmotorized lanes.