Complexity of Canadian traveler problem variants

Dror Fried, Solomon Eyal Shimony, Amit Benbassat, Cenny Wenner

Research output: Contribution to journalArticlepeer-review


The Canadian traveler problem (CTP) is the problem of traversing a given graph, where some of the edges may be blocked-a state which is revealed only upon reaching an incident vertex. Originally stated by Papadimitriou and Yannakakis (1991) [1], the adversarial version of the CTP was shown to be PSPACE-complete, with the stochastic version shown to be in PSPACE and #P-hard. We show that the stochastic CTP is also PSPACE-complete: initially proving PSPACE-hardness for the dependent version of the stochastic CTP, and proceeding with gadgets that allow us to extend the proof to the independent case. Since for disjoint-path graphs, the CTP can be solved in polynomial time, we examine the complexity of the more general remote-sensing CTP, and show that it is NP-hard even for disjoint-path graphs.

Original languageEnglish
Pages (from-to)1-16
Number of pages16
JournalTheoretical Computer Science
StatePublished - 27 May 2013


  • Canadian traveler problem
  • Complexity of navigation under uncertainty
  • Stochastic shortest path with recourse

All Science Journal Classification (ASJC) codes

  • Theoretical Computer Science
  • General Computer Science


Dive into the research topics of 'Complexity of Canadian traveler problem variants'. Together they form a unique fingerprint.

Cite this