karlsruhe: a ride on the "tram-trains"

 by Jarret Walker,
Human Transit
18 Sep. 2009

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Karlsruhe is a small city, about 300,000, with a very strong single downtown (including a major university) and not much to compete with it elsewhere in the city.  The geographical problem that drove the tram-train invention is that this urban core is about 2 km from the main rail station.  This separation is a feature you’ll find only in pre-rail cities (developed before 1850 or so) or some poorly planned late 20^th century ones.  In the main era of rail development, roughly 1850-1950, towns naturally grew up adjacent to railroad lines, and while the rail line itself tended to be an urban barrier, you typically ended up with a downtown that was adjacent to the rail station on at least one side of the tracks. 

If the city was there before the rail line, and the rail line couldn’t get closer without disrupting other travel markets, then compromises often had to be made between a station site ideal for the town and one that was efficient for the through operations of the rail service.  (The same tradeoffs are made today, at many scales, whenever land use and rapid transit interact in a new town or transit-oriented development setting.)

Karlsruhe is such a place.  Founded in the 18^th century, Karlsruhe is organised around a castle whose site was chosen to suit a royal ego rather than provide for efficient transportation, or for that matter, efficient anything.

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