The recent TGV speed record was won by a racecar-style one-off trainset that ripped up the track and the overhead to achieve a maximum speed that maglevs have already exceeded without destroying their running gear or rail infrastructure. The TGV is not ready to run 350kph with customers on a regular basis. Even the Nozomi700 shinkansen is maxed out at 300kph cruise.
Problem is air resistance goes up as the cube of the speed; aerodynamics only get you so far and getting large objects to go at airliner speeds at ground level through 1atm of air pressure requires massive amounts of energy, and existing fast trains are running into the problems of steel-wheel-on-steel-rail wear (think of multi-tonne hammer impacts on the rail from each wheel as the train passes over it) and catenary power delivery, both of which are severely exacerbated by high-speed running. The catenary wire has to deliver more power in a shorter period of time through the same-sized contact patch on the pantograph bar resulting in exagerated abrasive wear as well as spark erosion and (worst-case) melting. Maglev power is delivered through hot-shoe systems typically which have a greater contact patch area and less problems in power densities and wear.
Maglev is newer than steel-wheel-on-steel-rail and can still even in its current primitive forms outperform its wheeled ancestor speedwise. It's a bit like the first jet engines, crude though they were, which still produced power and performance matching the best piston engine designs of the day. It was obvious to a few visionaries (Sir Henry Royce among others) that they were the future of aero engines.
To get a speed increase out of the current in-service fast trains like the TGV and the shinkansens it may well be necessary to go to running in evacuated tubes to get rid of the air resistance problem, at which point 1000kph and higher will be a real possibility (LA to LV in an hour?).
Maglev speeds
Problem is air resistance goes up as the cube of the speed; aerodynamics only get you so far and getting large objects to go at airliner speeds at ground level through 1atm of air pressure requires massive amounts of energy, and existing fast trains are running into the problems of steel-wheel-on-steel-rail wear (think of multi-tonne hammer impacts on the rail from each wheel as the train passes over it) and catenary power delivery, both of which are severely exacerbated by high-speed running. The catenary wire has to deliver more power in a shorter period of time through the same-sized contact patch on the pantograph bar resulting in exagerated abrasive wear as well as spark erosion and (worst-case) melting. Maglev power is delivered through hot-shoe systems typically which have a greater contact patch area and less problems in power densities and wear.
Maglev is newer than steel-wheel-on-steel-rail and can still even in its current primitive forms outperform its wheeled ancestor speedwise. It's a bit like the first jet engines, crude though they were, which still produced power and performance matching the best piston engine designs of the day. It was obvious to a few visionaries (Sir Henry Royce among others) that they were the future of aero engines.
To get a speed increase out of the current in-service fast trains like the TGV and the shinkansens it may well be necessary to go to running in evacuated tubes to get rid of the air resistance problem, at which point 1000kph and higher will be a real possibility (LA to LV in an hour?).