What about the paragraph before that? > the service needs to be accessible, so either citizens need to be able to get to the buildings in a timely fashion, or

What about the paragraph before that? > the service needs to be accessible, so either citizens need to be able to get to the buildings in a timely fashion, or the buildings need to be able to send their vehicles out to various parts of town in a timely fashion. If traffic flow gets bad enough that this fails to happen, citizens get upset. All you need to have effective public services is enough capacity + traffic flow for your citizens to make use of them.