Comment by burkaman

This is how it already works in Europe (at least in Austria and Germany, but I assume elsewhere in Europe as well).

You will also find long trains that split in half mid-journey, so you need to make sure you get in the right car or you'll go to the wrong place.

Edit: I guess it's not exactly what you're saying, in Europe you will find platforms split into several sections with multiple trains to board, but they'll be for different lines with different destinations.