There has long been a suspicion that the $68 billion plan to build a 432-mile, high-speed rail system between Los Angeles and San Francisco was too little, too late. Essentially, some say, it could be the last hurrah for an outdated technology. “Bullet trains are obsolete, at the end phase of their development,” Rick Canine, an executive of Federal Maglev Inc., claimed in an interview two years ago. His company said it could build a magnetic levitation rail line with a top speed of 300 mph (to the bullet train’s 220 mph), similar to maglev lines already running in Japan and China. Maglev trains run on concrete beds with embedded magnets that repulse other magnets mounted on skis beneath lightweight aluminum passenger cars. Maglev drew no response at all from the California High Speed Rail Authority. Now comes Elon Musk, co-founder of PayPal, chairman of the San Francisco Bay area’s Tesla Motors and boss of SpaceX, the suburban Los Angeles company that has changed the resupply of the International Space Station. Musk agrees that bullet train technology is outmoded and would like to see that project aborted before much money is spent on it. He doesn’t endorse maglev, though he probably wouldn’t object. Rather, he suggests a completely new form of transport, essentially the use of a pneumatic tube to whip passenger capsules from place to place at hyperspeeds of almost 800 mph, right around the speed of sound. Hyperloop, as he calls his plan, would cost a fraction of the bullet train’s projected expense. Newspapers, department stores and banks once used similar technology to move paper through a pressurized tube for virtually instant delivery. The hyperloop would use far larger tubes for passenger capsules, which could travel form San Francisco to L.A. in about 40 minutes. There could be overheating and other safety problems, but Musk is also the fellow whose engineers conquered the problem of short range electric car batteries and who gets stuff into space at far lower cost than space shuttles ever did. Then there’s the route he chose: Musk would use 20-foot pylons along the I-5 and I-580 medians, the shortest driving distance between San Francisco and Los Angeles. Some have previously urged this much cheaper, swifter route, where the state already owns much of the right-of-way, but bullet train officials never so much as acknowledged those suggestions. So this plan makes some rudimentary sense, especially if the technology turns out to be more efficient than bullet trains. Bullet train authority chairman Dan Richard, said in a statement, that, “New technology ideas are always worth consideration.” But he added, “If and when Mr. Musk pursues his Hyperloop …, we’ll be happy to share our experience about what it really takes to build a project in California, across seismic zones, minimizing impact on farms, businesses and communities and protecting sensitive environmental areas and species.” It’s also true that the Hyperloop would not move quite as many passengers as the bullet train plans to, with a capacity of 840 per hour. So this proposal is in its infant phase at best, with many details yet to be worked out and the prospect of going forward only if the bullet train should be derailed by its persistent foes.