Document Type


Publication Date



Department of Mechanical Engineering-Engineering Mechanics


We study a Multiple Depot Heterogeneous Traveling Salesman Problem (MDHTSP) where the cost of the traveling between any two targets depends on the type of the vehicle. The travel costs are assumed to be symmetric, satisfy the triangle inequality, and are monotonic, i.e., the travel costs between any two targets monotonically increases with the index of the vehicles. Exploiting the monotonic structure of the travel costs, we present a 2-approximation algorithm based on the primal-dual method.

Publisher's Statement

© S. Rathinam, R. Ravi, J. Bae, and K. Sundar; licensed under Creative Commons License CC-BY 17th Scandinavian Symposium and Workshops on Algorithm Theory (SWAT 2020). Publisher’s version of record:

Publication Title

DROPS - Dagstuhl Research Online Publication Server

Creative Commons License

Creative Commons Attribution 3.0 License
This work is licensed under a Creative Commons Attribution 3.0 License.


Publisher's PDF



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.