Contacted VicRoads again. This time I spoke to David in Road and Traffic Management customer service. He was much more sympathetic to the situation than Sat and promised to pass on my concerns to the project manager for the works carried out. 30 minutes later the project manager, David Smith, rang me. The major points that came out of the conversation were

1. The work had been finished so there was not really anythin he could do
2. That the new barriers they put up should be most effective in reducing noise over short distances. He didn't have an answer when I told him that my unit is about 10-20 metres away and the noise had increased
3. He also didn't have an answer when I pointed out that gaps had been left under the barriers and in between panels. He promised me that the contractors would be out that weekend to put more earth and mulch at the bottom of the barriers. I am surprised that they work weekends. He mentioned nothing about fixing the gaps in the barriers.

Ref # 500503666