Unite Union's Newry branch is to stage a white picket on the Old Warrenpoint Road.
It's to urge drivers to reduce their speed.
The activists are also calling for traffic-calming measures.
The road's become an accident black spot with the most recent crash just last week.
The white picket is planned for Thursday at 6pm.
Woman in critical condition after she's struck by car in Belfast
Man dies following road accident in County Fermanagh
Executive will ‘have to deal’ with compensation costs from PSNI data breach
Man remanded in custody charged in connection with mosque burning plot
Woman charged over breaches at abortion safe access zone