This tends to be my rule of thumb. Speed Limit +10% assuming good conditions. It keeps me from being a hazard when other drivers wish to go faster while pretty

This tends to be my rule of thumb. Speed Limit +10% assuming good conditions. It keeps me from being a hazard when other drivers wish to go faster while pretty closely adhering to the whole point of speed limits. 7 mph over the limit on the freeway is still pretty safe. 7 mph over on a narrow residential street can be quite dangerous. This rule of thumb means I really don't have to waste any mental energy keeping an eye out for police, since someone else is almost always going faster and I find it doesn't significantly impact my trip times since traffic and stop lights tend to cancel out most potential gains from driving any faster.