Assuming your suggestion is possible, why wouldn't we just replace the road with railway tracks and move vehicles on flatbed cars instead? No one would need to

Assuming your suggestion is possible, why wouldn't we just replace the road with railway tracks and move vehicles on flatbed cars instead? No one would need to change their cars. And before anyone mentions throughput, let's assume we can use custom track sizes and just have people drive into the side of a railway car, like it was a ferry. Should be able to stack cars two height.