emergency vehicles are

automatically green-lighted through to the source of the alarm. The
physical operation of the city's port, constant and quite unthinkably
complex, is managed by another system. A "smart-card" system is planned to
manage billings for cars entering the Restricted Zone. (The Restricted
Zone is that part of central Singapore which costs you something to enter
with a private vehicle. Though I suspect that if, say, Portland were to
try this, the signs would announce the "Clean Air Zone," or something
similar.)