Today the Police launched the new non-emergency number "101" to replace the old, longer number 0845 8 505 505.
I had cause to use it at lunchtime to report a vehicle jump a red light that forced another pedestrian and me to run out of the way.
As I was ringing from my mobile, the automatic router put me through to a Police operator to ask my location. My call was transferred to the local area Thames Valley Police. My call was answered quickly and I passed on the incident's details. A couple of minutes later a reference number was texted to me.
The Policewoman was optimistic the driver might be caught as I'd notified the Police within 2 minutes and there's a camera monitoring traffic at Caversham Bridge. I was only able to give a partial number plate, but that still can be used.
Do dial "101" to report non-emergencies like mine. It is worth it as the Police use reported incidents to plan how to target their time & resources.