3-digit phone numbers like 411, 911, 511 etc.
411 / 511 / 911 are nation-wide reachable US phone
EMERGENCY number. A dispatcher will direct your call. Police,
Fire Dep etc.
Free - no
money / coins needed at public phones.
Directory assistance / service. Provides phone numbers and
Cost: varies from state to state. In New York City free.
Confusing may be that some states/cities require to dial a 1
before 411. Better you ask people before dialing.
A number of private companies offer a directory service under
different numbers. Charges vary.
Under this number you get traffic information nation-wide.
This service is called ITS (Intelligent
511 Travel Info is a project by the Department of Transportation
- the states are responsible for implementation.
So at this point the service might not be available in every state.