I don't think the Rock is considered a traffic nightmare and it's way further from the highway.
If we want NB to truly be considered a walkable city, which I think it mostly is, we need not be afraid of this kind of thing. People will take the train.
Further, people bus it to the stadium so if the basketball team is good they will do that then too. When I went to the RU-Michigan game, the stadium is very close to downtown Ann Arbor and people parked all over the city.
If the arena were to be on the CTown lot, which has been my proposal, you build garages on the east side of George Street down to the public safety building which double for Douglass use during school hours.
And RU needs to work as is with Pway to get some events and concerts at the stadium for extra revenue, so they should with NB as well.
except the Rutgers fanbase generally doesnt fit into the demo to use the train. RU hoops draws from Middlesex, Somerset, Union, and Monmouth Counties where taking the train is either not an option or its easier to just drive in. I think you overrate the amount of people using the train to get to New Brunswick...this isnt NYC or even Newark