The purpose of this paper is to provide a preliminary report on the first broad-based experimental comparison of modern heuristics
for the asymmetric traveling salesmen problem (ATSP). There are currently three general classes of such heuristics: classical
tour construction heuristics such as Nearest Neighbor and the Greedy algorithm, local search algorithms based on re-arranging
segments of the tour, as exemplified by the Kanellakis-Papadimitriou algorithm [KP80], and algorithms based on patching together the cycles in a minimum cycle cover, the best of which are variants on an algorithm
proposed by Zhang [Zha93]. We test implementations of the main contenders from each class on a variety of instance types, introducing a variety of
new random instance generators modeled on real-world applications of the ATSP. Among the many tentative conclusions we reach
is that no single algorithm is dominant over all instance classes, although for each class the best tours are found either
by Zhang’s algorithm or an iterated variant on Kanellakis-Papadimitriou.
Supported in part by NSF grants IRI-9619554 and IIS-0196057 and DARPA Cooperative Agreement F30602-00-2-0531.