Deliver a letter from SOMA to UCSF

I need a letter delivered to UCSF on Tuesday afternoon. It'll be ready for pick up in SOMA by 2:30 (latest) and must arrive at UCSF no later than 4:00. The drive is under 15 minutes, but with finding both locations, it could take 40-50 minutes total. This letter is an application, so reliability is the most important thing.