it depends on the abuse they take
Well a train need not be steered, only the speed needs to be controlled. The train follows the track due to the grooved wheels. Quite right. The wheels are known as 'flanged' wheels- there is a lip that runs around the inside edge. This allows the wheels to be guided by the track & not slipping off. Speed, direction (forward or reverse) & stopping are the three major situations the engineer controls.
You need the front rotors machined or replaced.
The filters are what needs to be replaced most often on the air conditioning units.
Maglev (magnetic levitation) trains run by way of a magnetic field generated by magnets embedded in the track. As such, they have little or no need for wheels.
It depends on the use, but yes, they have to be replaced periodically.
3 months i think
The Honeywell filter should be replaced every 8- 12 months or as needed.
They need replaced when they wear out.
This depends on how much your car is exposed to the elements. In areas with poor weather, it will need to be replaced often.
Credit cards typically expire every 2 to 3 years and need to be replaced with a new card.
Check your wheel bearings, or you might need a wheel alignment
they never need to be relubricated just replaced