Iron Horse is a train card game (by R. K. Geier, published 1983 by Icarus Games) that uses a clever idea of distance between cities based on their Cartesian coordinates. The distance between 2 city cards is dx+dy (aka the Manhattan metric). Cities at the same coordinate are distance 1, rather than 0. E.g. the distance between Seattle and Chicago is 3+1=4. The distance between Seattle and Boise is 1. The United States are laid out on a 6x3 grid (with the southeast corner having no cities).

Boise Portland Seattle	Billings	Bismarck	Milwaukee Minneapolis	Buffalo Detroit	Boston Portland
Las Vegas San Francisco	Denver Salt Lake City	Kansas City Oklahoma City	Chicago (x4) St. Louis	Cincinnati Cleveland Pittsburgh	Baltimore New York (x2) Philadelphia Washington
Los Angeles (x2)	Albuquerque Phoenix	Dallas Houston	Memphis New Orleans	Atlanta Charleston Miami

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