Hi,
What you have to realize is with a linear induction motor, the field is open in a flat plane, with a rotary induction motor the field is in a circular plane.
In a circular system you enclose the field and can make clearances extremely tight, due to bearings.
The motor only has to use its energy to rotate the load.
In a linear system like transport, you have an open field that is not just propelling the load but supporting it to obtain ride clearance.
Any advantage from mag lev to reduce friction is used to levitate.
It is surprising how efficient a train with steel wheels on a steel track, with proper wheel and rail profiling can be.
Tom... 