Car park ramps carry traffic every day and lead to the lowest level of the site, so they usually get an automatic or passive barrier. The automatic barrier suits centres with a reliable power supply and a central control system for lowering and reset; the passive barrier needs no power at all, so it suits ramps where supply cannot be counted on during a storm.
Public entries and loading docks are usually closed with aluminium sets, made for each opening and stored nearby. Each set needs a person to fit it, so on a large centre it pays to write down who fits which set, and in what order, before the Bureau issues a Flood Watch.
Tenancies with their own street doors are treated like individual shops: aluminium where the landlord allows fixings, ABS or Oxford barriers where nothing can be fixed to the shopfront.