A replacement bridge on State Highway 82 in South Canterbury has been completed at roughly half its projected cost, the government says.

The new two-lane Elephant Hill Stream Bridge cost $3 million to complete, against an original budget of $5.7 million. Construction took three months.

Associate Transport Minister James Meager said the original single-lane bridge was more than 100 years old and had reached a point where replacement was more cost-effective than ongoing maintenance.

A second bridge replacement on the same highway, the Waihao North River Bridge 12 kilometres away, is on track for completion by the end of the year at a projected cost of $14 million.

Both projects are funded through the National Land Transport Programme 2024 to 2027.

SH82 is described by the government as the only alternative route to SH1 for traffic travelling north and south of the Waitaki River.

Meager said the new concrete structures carry no load restrictions, improving conditions for freight operators.

Waitaki MP Miles Anderson said completing the project on schedule and below budget was an outstanding achievement by the NZ Transport Agency.

The government said nine priority bridges and culverts were approved for repair or upgrade in July 2024, with a further five locations added since.

NZTA is progressing design, consenting and contracting on those sites.​​​​​​​​​​​​​​​​