A method is disclosed which enables travelers to discover other travelers with similar and compatible travel plans, for purposes of contacting them and negotiating shared travel agreements. Travel plans are characterized quantitatively, enabling numerical measurement of the match between a pair of plans. Dependence upon similarity of place names is eliminated. The temporal difference between plans is converted to an equivalent distance difference and summed with the origin and destination differences to yield a single number ranking the match. Plans are ordered by this ranking against a search specification. The method is more compatible than the prior art with computer automation, and is accessible via the Internet.