Central Otago District Council roading engineer Scott Graham said last week that although the underpass would not be officially opened until next month, it would be open for public use within ''the next week''.
Workers were putting the ''finishing touches'' on the underpass, which included the final timber retaining wall on the Clyde side, as well as pouring concrete for the paths.
The council would host an official ribbon cutting ceremony at noon on July 24. The project is costing about $500,000.
Central Otago Mayor Tony Lepper said the underpass was a great example of ''collective'' effort combined with an ''approach to funding that has allowed a seemingly impossible safety project to be completed before an accident happened''.
Work began on the underpass in mid April, after years of campaigning and support from residents, businesses and community groups, as well as Clyde Primary School.
The underpass will create a safe passage for school pupils and other residents, as well as users of the rail trail, to cross the highway, which separates the rail trail terminus from the Clyde township.
Clyde School principal Doug White said the school was looking forward to an ''almighty celebration'' at the opening next month.
''It will be an asset to the town and the wider community,'' he said. Promote Dunstan secretary Louise Joyce said her group had been in contact with Dunstan High School about pupils painting murals on the walls but still had to get permission from the New Zealand Transport Agency.
If permission was granted, one wall would show the inside of a train carriage and views of Central Otago, while the other would show the outside of the train carriage.
