Any bike can be used for 2x 1.5 miles.
Look at the ratio of cycling duration vs prepping time: you want a grab-and-go convenient bike. There is simply no advantage to riding fast at the expense of convenience.
Fit fenders and possibly a chain guard. Ride in work clothes.
Fit Schawalbe Marathon Plus, the most puncture-resistant tyre (no repair kit needed).
Fit dynamo (hub) lights. Fit-and-forget, always available, no removal needed.
Fit front basket or rear rack. Get a lock that stows for quick access.
Pick transmission suitable for the terrain: 3x9, 1x8, 8-speed internal (IGH), 3-speed, singlespeed.