Hamburg's lost over-and-under monorail

Hamburg's Cabintaxi was an "over and under" monorail design that ran personal monorail cars in both directions, with counterclockwise traffic on one level and clockwise on the other. It looks like it never got deployed, but it's one sweet retrofuture design for urban transport:
The computer now takes over completely. It regulates our speed, senses the position of any car ahead to maintain a safe headway, and holds us at intermediate stations only if the track is temporarily occupied. We’re programmed for travel to the selected destination by the most direct path. Upon arrival, the car is released for immediate use by other travelers.

“Our over-and-under guideway is a big space-saver and cost-cutter,” MBB’s Gert von Lieres told me. “A two-level guideway can fit into narrow streets that couldn’t accommodate parallel rails, and there’s less clutter in the streets from support columns. Construction is simplified and thus relatively cheap.”

It’s also a quiet system; the cars glide at about 22 mph on rubber-tired wheels. And it shouldn’t be affected by weather; the base, suspension, and guidance tracks are fully enclosed within the beam. “This protects them from snow and ice,” von Lieres said, “while the lateral rollers eliminate any risk of derailment. They allow tight corners—a turn radius as small as 100 feet—meaning greater versatility in urban routing.”

Over-and-under monorail — a single beam tor two-way taxis (Jul, 1980)


    1. Schwebebahn ftw!

  1. But this would have been better than the Schwebebahn, right? Same footprint as the Schwebebahn, but twice as many trains.

  2. How can anyone not like these kinds of things? These types of systems should be all over the place. Why is it that these types of systems only seem to be installed in places that are probably fairly pedestrian-friendly to begin with? They’d be great in areas like Southern California, where walking is a death wish.

  3. Looks kind of like the monorail used in the “Fahrenheit 451” movie.  However, I think that set location was actually in France.
    22 MPH?!  Let’s pick up the pace.  People can ride a bicycle faster than that-Though I wouldn’t want to race to work in the rain on a bike…  But couldn’t we get the speed up to 60 or 70MPH?  And since we’re looking at modern transportation, I again ask, “Where are the flying cars I was promised we’d all be using by this time?”

  4. PRTs are a pet topic of mine and the Cabintaxi was one of the cleverer designs of the time. PRTs have always been the safest and most convenient of possible forms of personal transit, combining the environmental virtues of mass transit, the conveniences of private vehicles, and the inherent safety and improved speeds of tracked transit. Get in, pick a destination, and sit back and enjoy the ride. Early systems were slow but in recent times systems supporting linear motor propulsion and mag-lev have offered the potential of far-higher than automobile speeds. One of the most successful deployments was in the US with the Morgantown PRT at the UWV. But it has always been a tough sell in a culture dominated by the oil and automotive hegemony. It has alway suffered from a need to be fully integrated into the architecture of an urban environment to maximize its potential. And designers have often overlooked the power of integrating PPT (personal packet transit) into these systems. Still, the concept persists to this day with thing like Masdar’s automated cars. SlyWeb/Taxi2000, and Skytran. One of the most fun-looking is a German designed system derived from roller coaster technology called CityCoaster. (

  5. What I find interesting is that detractors of a monorail in LA often cite our earthquakes as a concern, but we live with huge concrete overpasses from the freeway system (and they have proven both  hazardous and expensive to repair from earthquakes). No matter how we solve our transportation problems, we are at the limit of spreading across. We’re at the point where we can only move up, and that means either more stacked concrete or a new solution. I live in Long Beach partially because of ready access to public transport, and I believe if a decent system was built, people would ride.  

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