Those crossing the Clutha River at Beaumont may have to make use of a temporary road from next week, as construction of a new bridge across the river continues.
A 600 metre temporary road is being built so new bridge approaches on State Highway 8 can be formed.
The single-lane, sealed road will be controlled by traffic signals 24 hours a day - and may be in place for a year or more.
Waka Kotahi says the temporary road is needed as State Highway 8 is being realigned to meet the the new bridge.
The old single-lane Beaumont Bridge was built in 1887 and road users in the area have been calling for a new bridge for years.