Optimization Framework for Bicycle Network Design

Abstract

This paper presents a new formulation for the network design problem as it relates to retrofitting existing roadway infrastructure for bicycles. The goal of the problem is, for a minimum cost, to connect all origin–destination pairs with paths where each roadway segment and intersection meets or exceeds a lower bound on its bicycling level of service. The length of each optimal path is constrained to be no greater than a given upper bound, which is expressed as a function of shortest path length. Experimental analysis on the Austin, Texas downtown region shows that a systems approach will yield different results than an approach that separately considers connecting each pair of origins and destinations, and that placing an upper bound on the amount of deviation from the shortest path will impact the design decisions. Model parameters, although the defaults are based on existing research, should be calibrated based on local data. Variants on the formulation are provided that allow for a trade-off between optimality and computational efficiency.