A Continuous Deviation-Flow Location Problem for an Alternative-Fuel Refueling Station on a Tree-Like Transportation Network

Table 2

Comparison among three methodologies for solving an AF refueling station location problem.

	Kim and Kuby [20]	Ventura et al. [18]	Proposed solution approach
Objective function	Maximizing the total traffic flow covered by the station	Maximizing the total traffic flow covered by the station	Maximizing the total traffic flow covered by the station
Set of candidate sites	(i) Predetermined; (ii) Finite (vertices only)	(i) Transportation network; (ii) Infinite (anywhere in the network)	(i) Transportation network; (ii) Infinite (anywhere in the network)
Deviation	Yes	No	Yes
Deviation paths	Endpoints of deviation paths must be vertices	N/A	One endpoint of a deviation path must be a vertex and the other can be any point along the network
Main constraints	(i) Number of refueling stations; (ii) Vehicle driving range; (iii) Distance decay functions for traffic flow rate on deviation paths	(i) Setting up an initial refueling station; (ii) Vehicle driving range; (iii) Positive traffic flow rate for some short trips	(i) Setting up an initial refueling station; (ii) Vehicle driving range; (iii) Portion of drivers who select the deviation option
Global optimum	No	Yes	Yes
Computational complexity	NP-hard	Polynomial ()	Polynomial ()

= number of vertices.