Nobody from Brighton will be taking the train. They have to drive to that station west of town, to Hamburg, or Whitmore Lake. Why bother. 95% of everyone would have to drive to the station anyway.
I grew up in Brighton, over on Kensington Rd and we had our family business on Grand River just east of town. Lived in AA for several years and drove against traffic to work but noticed not a whole lot of traffic was actually going to AA, but around 14 and then on to 94, Yes the exits got busy, but I really don’t think it is going to make a huge difference at all myself.
What it WILL do is let students get out away from the city and still get to school while saving a lot of money over AA prices, if I owned rental properties out that way I would be cheering the train idea.