Speed camera staff are to begin a 72 hour strike at 9am this morning.
At least half of Go Safe's employees will strike in a dispute over working conditions and union recognition.
Garaí are to fill the gap as the strike leaves 1 in 8 speed camera vans unmanned this weekend.
A spokesperson for the company said it has "moved early to ensure disruption caused by SIPTU's action will be minimised."
The added that safety cameras will continue to be operational over the entire Bank Holiday weekend.
Road Safety Authority chief executive Moyagh Murdock is calling on drivers to stay safe on the roads: "We're entering into the bank holiday weekend and also we see the clocks going back so the message from the Road Safety Authority is to urge everybody to be vigilant and to respect the rules of the road and be responsible.
"It's a holiday for people but the roads are no less dangerous on Bank holidays so you need to be vigilant and never, ever drink and drive."