It’s done in various places. NJ Riverline is an example. There are a bunch of others. The bigger problem is the freights just have no interest in sharing the t

It’s done in various places. NJ Riverline is an example. There are a bunch of others. The bigger problem is the freights just have no interest in sharing the tracks with passenger trains, and requiring heavier and more expensive passenger trains is a convenient way to price the project to death.