The 37-kilometre upgrade, scheduled to begin next year and be completed by 2020, will finish on Colac’s eastern outskirts and link with the congested single each-way road through the city centre.

According to a special planning panel report on the huge project, the roads authority indicated a Colac bypass “may be on the agenda in the future and submitted that the preferred route for this is unknown at this stage”.

“In the meantime, VicRoads submitted, an upgrade of the existing highway through the town to provide turning lanes and a better standard of pavement within the existing road reserve would be the most appropriate approach”.

Colac Otway Shire Council advised the panel a heavy-vehicle bypass was mentioned in its municipal strategic statement, but there was no identification of a preferred route and any bypass was likely to be many years away.

“The panel is therefore not in a position to comment on how the duplication project will integrate with a future bypass,” its report said.

VicRoads has proposed a new single-lane roundabout at Baillie/Gallop streets to abut the duplicated highway section.

However, the panel questioned the appropriateness of a roundabout, which would be the only one on the highway between Warrnambool and Melbourne.

“The panel also questions the choice of roundabout given relatively low volumes of traffic on intersecting roads and the relative difficulty of negotiating a single-lane roundabout for heavy vehicles,” the report said.

“The panel believes traffic signals may be more suitable.”

VicRoads will finalise an “adoption report” where the panel’s recommendations are reviewed and responded to before being sent to the Planning Minister for approval. In the meantime VicRoads representatives will continue meeting with landowners affected by compulsory land acquisition. 

Colac Otway Shire Council has asked that views across Lake Colac from the highway should be preserved and that the Barongarook Creek should be upgraded with a cantilevered pedestrian footbridge.

Environmental concerns about loss of vegetation and threats to wildlife have been addressed.

The panel said proposed works on waterways, control of disease transfer and a conservation management plan would minimise impact on the growling grass frog.

Management of  Birregurra Creek and other aquatic habitats was  also considered   helpful in minimising harm to the hairy burrowing crayfish.

The project will link with the soon-to-be-completed duplication between Waurn Ponds and Winchelsea with two 3.5-metre sealed lanes on each carriageway and a dividing median strip of variable width, but usually wide enough to park a 25-metre long truck.

 Statistics show there were 32 crashes between Winchelsea and Colac from 2008 to 2012, including three fatalities and eight serious injuries.

Traffic volumes are increasing by about 3.5 per cent a year and recent figures range from 6000 to 9000 vehicles a day, including 900-1800 heavy vehicles.