The installation of safety barriers on Brisbane's Story Bridge will be complete before the end of the year, the Brisbane City Council says.

It comes as a mental health advocate says the measure has taken "far too long", and recent Griffith University research shows barriers significantly reduced jumping deaths at Brisbane's Gateway Bridge.

Story Bridge. Credit:iStock

Brisbane City Council announced the $8 million suicide prevention barriers in 2013 and had initially set mid-2014 as a finish date.

However construction was stalled due to heritage issues with the bridge, opened in 1940, and works were expected to be finished in June 2015.