911 should be used any time you need a police response, emergency or not. This might include: filing a police report for an alleged crime (in progress or not), reporting a traffic accident, illegal parking, noise complaints, road blockages and/or hazard, dangerous drivers, leash law violations, prostitution, attempted scams, financial identity fraud, credit card fraud, suspected elder abuse, misuse of sidewalks (skateboards, hover boards, electric scooters, and other similar conveyances), door-to-door soliciting, panhandling, etc.
911 operators are trained to prioritize calls and assign report numbers. When 911 is bypassed, Davidson officers, etc. still have to route the call through 911.