Back from the Arboretum - nice place, too darn hot, hall will be fine for our show. Went to get back on the freeway home - onramp closed. Went west on a major street to the next entrance - onramp closed. Same for the next one. At that point I had two choices - go berserk, usually that's my default, or enable GPS to take me home. I chose the latter. Since it by-passed every single onramp for the next ten miles until I was at the final onramp before moving out of Pasadena, I assume something untoward was/is going on.