There's still a few old ceramic and concrete street signs around town that were made before 1930 and there are about 100 cast iron plates in service that were installed between the 1930s and 1960s - they were hand-crafted and can weigh up to 30kg.

There was a change of design in the 1960s to 1970s with the plates made of concrete again, then there was a new design and now the most recent ones are made of aluminium - they began in 2005 when 19,000 street signs were replaced.