Modelling speed–flow relationships for bicycle traffic flow

Speed–flow relationships used to describe speed characteristics are very useful, especially as they can be utilised to analyse capacity and level of service. Speed–flow relationships for motorised vehicles have been widely studied, but those for heterogeneous bicycle flow have yet to be examined. This research thus aimed to develop speed–flow relationships for heterogeneous bicycle traffic flow, incorporating the factors of bicycle type and characteristics of cyclists such as percentages of electric bicycles (EBs), male cyclists, elderly cyclists and cyclists carrying loads. On the basis of field bicycle traffic data from 11 cycleway sections, three speed–flow relationships for different numbers of cycleway lanes were developed. The three models were further validated and used to examine the effects of bicycle type and characteristics of cyclists on the speed–flow relationships for bicycle traffic. The results showed that bicycle speed increases with the percentage of EBs on the cycleway, while the proportion of elderly cyclists has no significant effect on bicycle speed. Cyclists carrying loads and male cyclists have negative impacts on bicycle speed for a narrow width of cycleway. The findings of this study provide some countermeasures for bicycle planning and management.