Talk about having the worlds largest power bill. Maglev and Electromagnets operate on the same priciple, and using superconductors is going to be so insanely expensive (There is 33 billion meters of road) that you might as well build proper space elevators and use rockets to travel.
The simple issue is, there is nothing quite as effective, cheap and all purpose as having a wheel on your vehicles.
- Works off road and on road
- Requires no power
- Inexpensive compared to maglev and super conductors
- Easy for a normal person to replace (with some training)
Situations where wheels are better:
- If there is a black out
- In a natural disaster
- After an earthquake
- Parking on a hill
- When you just have enough money to make rent and don't want to spend money to keep your car levitating
- When you want lower taxes, because everyone needs to contribute to the electricity bill to keep all the roads on 24/7
- If you don't to make all small electronics basically float or melt
There is one scenario I know of where maglev technologies would be good and thats
- If you want to go very very very fast in a single direction
If you want to counter point all these arguments, there is still one factor you can't beat. Cost.
Wheels are simply cheaper no matter what you do. The only thing cheaper than free electricity is requiring no electricity. Rubber is naturally cheaper than any superconductors or electromagnets and the tires won't need to be connected to the grid.
So wheels themselves will never be made redundant. That doesn't mean the super rich can't also have their own floating cars (essentially private planes).
=== Expanding why it costs a lot ===
Electromagnets are expensive in general. It requires a lot of wiring and metal in general and you need to make sure everything is robust enough to handle basic damage. Thats people dropping things on it. Car crashes. Thunder strike resistance. Then there are the two biggest issues are Heat changes (Winter and summer temperature differences) which will cause the material the expand and shrink and Water/Rain. Making things "Proof-able" is expensive in general. You need to cover 33 billion meters of road (the current amount of road) + All driveways, dirt roads, country tracks etc. This is compared to the current model of sticking 4 wheels and a spare one onto a car.
Manufacturing costs and material costs wont reduce just because its the "Future". People need to get paid to extract, manufacture and install these things. The cost of replacing 33 Billions meters of road with essentially metal isn't going to beat the current cost of 0. Because we don't need to replace anything right now.
Super Conductors are also expensive. Even if they work at room temperature. Your talking about a Non-Existent material being cost effective verses a Current, Widely available and Cheap material. Heck, it might even be renewable now that we can literally make it out of plants. Even if you throw in 300 years, you seem to think that the price of rubber and plastic won't go down in time along with the cost of the ceramics used to construct your super conductors. Your talking about the assembly of multiple materials at a scale so large the world can't even deal with it in its current shape.
So yes. Steel now-a-days is cheaper than it was 300 years. Largely due to improvements in manufacturing and mining. Duh... 300 years. By that metric, rubber has become even cheaper. Being virtually none existent, to being so abundant we can literally throw away a countries size worth and just let it sit there.