Sadly, the speed kills myth is alive and well in Pennsylvania. A real 25-state analysis was done on NHTSA data, which showed that 1.6% of crashes are caused by excessive speed. Barely above zero, then.
Nowhere does anyone ever put into a bill that speed limits must be posted at the 85th percentile free-flowing traffic speed. This is so that the ticket industry can thrive. Set the limits too low, ticket barely above them, get municipal radar and speed cameras, then watch the money flow in. Since this is still not enough, the state now wants more LIDAR and moving radar. You can expect more crashes, safe drivers cited, and lots of erroneous tickets with poor policies.