The speeding on this stretch is rather ridiculous, but 15mph is too low. I think increasing it to 25mph just on this straight stretch and leaving the rest of Scottsdale at 15mph would be fine. I have seen people partly in the crosswalk and cars not yielding to them. Most recently a family was in the crosswalk and a car came barreling down probably at around 45mph just to make the light to cross Baltimore. This area might need one of those free standing radar devices that shows the speed limit and the speed you are actually travelling. Maybe that'll act as a deterrent.