The volunteers could then practice their skills getting people out of the wrecks.
He said the exercise was to "just replicate what we would find on the road".
"The students respond to the set-up and apply their skills to what they would find on the road," Mr Weston said.
He said the instructors, which included senior station officers such as Bryce Coneybeer, had a "wealth of knowledge".
Mr Weston did not attend the exercises, but said it was common to get "a few curious onlookers".
"Sometimes they're quite realistic, what they set up."
Occasionally the fire service would put up signs to let members of the public know it was simply an exercise, Mr Weston said.