Can you drive through campus with a Union

which part of campus?

I want to cross Highland on Darymple and then left on Tower. I want to drop off some heavy Tailgating gear then pass in front of the Union toward the parking garage.

The intersection of Darymple and Highland normally has security that lets you through if you have parking pass on campus, but this is the first time I've ever had a pass for the Union Parking Garage.

It's really the Bookstore Garage but that's what the ticket office calls it

I have a parking pass for the Union Square Parking Garage, and for both games this year I have used it to drive through campus. Specifically, I entered campus from the west side (from Nicholson Drive) and went through the parking pass check point that's on Cypress Dr. near its intersection with W. Chimes Street. I did it for the same reason you are trying to -- in order to drop off some tailgating stuff on the circle around the parade grounds while on my way to the garage. Both times the guard at the check point stopped me momentarily because he had never seen that parking pass before. After I politely explained to him that the pass gives you access to the parking garage, he let me through. Once you get through that checkpoint, you are into the restricted parking area and are good. You can get to the parade grounds without being checked again.

You might have a harder time if you want to get there via the route you are trying to take -- i.e by crossing Highland and going through the checkpoint that's right there on Dalrymple. There is just no reason that you would need to go through that particular check point, coming from the direction that you would be coming, to get to the Union Square Parking Garage. Come in from the west side of campus though like I did and there is in fact a reason that you need to get through the Cypress Dr. checkpoint in order to get to the Union Square Parking Garage.