A static green bike repositioning problem with heavy and light carriers

Abstract

<p>Heavy carriers like fossil fuel trucks are widely used in conventional repositioning activities in bike-sharing systems, while the consequent fuel consumption undermines its environmental-friendliness. This study investigates a static green bike-repositioning problem with heavy and light carriers (e.g., bike trailers), aiming at minimizing the total cost, including the expected penalty costs for user dissatisfaction, internal variable costs (operating cost and fuel cost), and the external cost. Mixed-integer linear programs are presented with different objectives simulating the goals of public and private operators, respectively. The results show that incorporating light carriers into the repositioning fleet can reduce both the total cost and fuel consumption compared to using heavy carriers solely under the following circumstances: 1) the unit penalty cost, the average nodal distance, and the average absolute deviation are low to moderate; 2) some stations are hard to access for heavy carriers; 3) the traffic on the main roads is congested. The result also illustrates that by charging private operators a high cost on emissions, using more light carriers can be beneficial in reducing both the total cost and the fuel consumption, but user satisfaction and profits for the private operators are sacrificed. This implies that a subsidy to the private operators may be called for if environmental considerations are imposed on their repositioning decisions.</p>