Comments on: Continuous approximation models in freight distribution management

Abstract

The paper presents a review of the use of continuous approximation modeling for freight distribution management. The authors take a unique approach to reviewing continuous approximation models in the freight distribution literature. They anchor their review around an in-depth analysis of two fundamental results upon which much of the continuous approximation literature is built: the asymptotic approximation formula for the optimal traveling salesman problem (TSP) tour length from Beardwood et al. (1959) and the strip strategy to build implementable TSP tours from Daganzo (1984). Whereas other continuous approximation survey papers focus primarily on application areas and the resulting advances in methodology [e.g., Langevin et al. (1996) for the period up to 1996 and Ansari et al. (2017) for the period from 1996 to 2016], this paper structures the review in the context of these two seminal contributions. As such, the authors create a valuable narrative of the evolution of continuous approximation models.