A big difference is that many taxes for using roads are paid regardless of road use, whereas a train ticket is obviously priced for the usage. (Yes, gas tax can indirectly be this, but different vehicles have vastly different fuel economies, and people also buy some amount of gas for non-road use; of course toll roads are by-usage, but most roads are not toll roads.)

> we didn’t pay for the track in most cases

Could you elaborate?

> now they want to add another

There are plenty of existing toll roads, bridges, and tunnels. It’s not really a new idea.