The closure of the Beaumont Bridge for two days next week, requiring an 80km detour for heavy vehicles, is the first of several closures, though not all will require detours, the New Zealand Land Transport Agency says.
NZTA project team manager Simon Underwood said work to make the bridge strong enough to carry up to 62-tonne vehicles without a permit would require further intermittent closures through June.
The closure was ''not something we take lightly'', he said.
More work would take place over a year starting in June, but he could not say whether that work would require detours, Mr Underwood said.
The closure was to replace a previously repaired load-bearing beam damaged in a vehicle crash.
Steel plates would be added in subsequent work so that by June the bridge would be made ''high-productivity-vehicle'' capable.
The bridge was not included as a priority for replacement until the 2018-21 regional land transport programme.
The detour would add 20km, or 15 minutes, for most drivers, who would be required to drive through Balclutha and on to Clydevale before passing Beaumont.
An 80km detour would be in place for some heavier trucks, which would need to detour through Tapanui.
