During the construction process, this steel plate was omitted. Later, two other road signs under inspection were found to have the same problem.
(Image source: Herald Sun)
In fact, these street signs did not deteriorate, but they were taken down as a preventive measure.
Design guidelines for the three gantries built during the CityLink Tulla widening projectRegulations, Steel plates must be installed inside them to strengthen the connection between metal and street signs.
These components, called stiffeners, were supposed to be installed in the gantry, and VicRoads staff is unlikely to find this problem during the initial inspection.