A planned upgrade to the traffic signals at the intersection of Victoria Ave and Glasgow St will begin on Monday.
Whanganui District Council senior roading engineer Brent Holmes said the traffic signal equipment at the intersection was out of date and they were no longer able to obtain parts to maintain them.
"In addition the intersection provides limited pedestrian protection at the crossing points, and considering Whanganui's recent and future growth, this is no longer acceptable.
"It also has the highest number of crashes for a signalised intersection in Whanganui."
Work on the signal replacement will begin with drilling of new cable ducts under the approaches to the intersection. Some work will take place at night to reduce disruption.