Great topic, and good thinking.
I found this too just to throw in the pot.
911
In most if not all parts of the USA and Canada
the telephone number for contacting the emergency services (fire, police and ambulance) is 911,
equivalent to the British 999 number. This number must only be used in an emergency.
311
In some US cities,
a non-emergency telephone number for contacting the police.
In some US cities, a telephone number for contacting the city authorities to report problems such as faulty street lights, potholes in roads, etc.
Others yet to be seen.
511
According to some sources there is a move to introduce
511 as a national telephone number for current road and traffic information across the whole
of the USA. I get the impression that this plan is still in a very early stage of being implemented. According to a news story in USA Today
14-Jul-03, Washington State was the sixteenth state to start using 511 as a traffic information telephone number.
It's reaching, but maybe???