Thursday, May 10, 2012

Replacing conventional transportation paradigm faces major technical hurdles


After looking into the details of personal rapid transit, I've concluded that it's tough to find a practical and complete alternative to the existing system of vehicles under human control. SkyTran appears to be a hoax. Practical personal rapid transit (PRT) systems have been developed, and India is having one installed in one of its cities. The vehicles are battery-powered, and I suppose that discharged batteries can be swapped with charged batteries to minimize vehicle down-time.  One of the main advantages of this system is that once a vehicle starts moving, it won't stop until it reaches the destination, so it's very efficient.  But I suspect that it would have problems adapting to cold climates.

The main problem with maglev PRT seems to be the fact that the "bogies" (the parts which interface with the track) are not compatible with tight turns or track switching, because of the small clearances required between the track and the bogies to generate the required lifting, acceleration, and deceleration forces. If this could be overcome, I suppose it would have been by now, because a lot of mechanical engineers have been looking for solutions for a long time.  I thought they had found solutions, because SkyTran is being advertised as a proven solution, even though it's just a vague concept.

Meanwhile, engineers are designing conventional vehicles that will assist drivers by keeping the car in the middle of the lane, or applying the brakes to avoid a collision. These improvements will still require the driver to be in control at all times, or prepared to take control at any moment, although I suppose there will come a time when drivers will be able to drive while distracted or impaired, or doze off on long straight stretches of highway, without significant risk. Google has designed an autonomous vehicle which has proven to be very safe, but is required to have two people on board to drive it in traffic, in case something goes wrong.

The high cost of fuel is another major transportation issue, but it doesn't appear to be a technical one.  It appears to be partly intended to help bail out the financial system, and to reduce the use of our crumbling road system, which isn't being replaced because our great leaders don't expect us to be around much longer.