Invercargill City Council group manager infrastructure Erin Moogan said the intersection had been identified as a high-risk area, with 18 crashes recorded there in the past five years.
"The new improvements will mean reduced speeds and conflicts between vehicles, and ensure safe negotiation of the intersection.
"This will mitigate and minimise the risk and severity of incidents."
The works were completed ahead of schedule last week and also provided improved pedestrian crossing facilities and cycling infrastructure.
"To see these major works completed, ahead of time, is a great addition to the community and will be a lot safer and easier for the public to now navigate," Ms Moogan said.
Improvements were made to drainage, kerbs and channels, chipsealing and asphalting at the same time as the lights installation.
"We’d like to thank all local businesses, residents and road users for their understanding and patience while these works have been occurring.
"We’re hopeful that the end result is one that will keep the community and all road users safer," she said.
