Estimation of influence width and shy-away distance of parallel curb parking on undivided urban roads: a theoretical approach

Curb parking is a common feature in urban road segments. While it provides benefits to the local merchants and is popular among the road users, the majority of municipalities and transport officials are of the opinion to remove it due to its immediate consequences. The presence of curb parking reduces the carriageway width available for regular traffic and subsequently, lowers the capacity of the road. Therefore, the relationship between the curb parking intensity and the roadway capacity holds significance and has become a crucial aspect to be considered before allowing curb parking on an urban mid-block. To quantify the curb parking intensity, although several measures are available, each one of them has some innate limitations. In this context, the present study forwards a novel measure called ‘Influence Parking Width’ which addresses the limitation of an existing measure and contributes toward the more meaningful quantification of the curb parking intensity. Further, this paper proposes a theoretical approach to estimate the ‘influence parking width’ (PW I ) and ‘shy-away distance’ (SW) caused by the presence of curb parking on undivided urban roads. To this end, since the field estimation of the actual parking width (PW A ) is relatively easier, the study has forwarded an empirical model so that the proposed influence parking width can be predicted for a given actual parking width. The study revealed that as PW A rises to 1.42 m, SW rises as well, reaching a maximum value of 0.95 m. However, beyond 1.42 m, a further rise in PW A causes a reduction in SW.