Mailbag: Stony Point speed limit? U-turns in front of schools?

Here's a question from a reader: I'm wondering if you can clarify the speed limit on Stony Point Road between Rohnert Park Expressway and Petaluma Blvd. North. If you are heading south on Stony Point, just a bit after Rohnert Park Expressway, there is a sign that says "End 50 [...]