Yes, traffic slows at some intersections, and then too many drivers hit the gas and go way too fast until the next choke point.

I am aware the speed limit was changed to 30 mph - for the area of 39th I was on, back in the 90s, and for an area further south, several years ago. Unfortunately, most studies I've read indicate that changing the posted speed limit doesn't affect driver behaviour - you need physical traffic calming measures, or serious enforcement, to do that. As a result, speeding is rampant on that street.

So, anyone want to answer my question? If you were friends with the cyclist I saw, would you recommend that she keep riding 39th at night at her pokey 10 mph, as long as she takes the whole lane? Would that be your best advice to her?