Met Eireann has issued a Status Yellow Rain warning for the whole of Ireland.
The forecast is for high amounts of rainfall over the weekend that may cause disruption.
The warning is valid from 9pm on Saturday until noon on Sunday.
The Road Safety Authority (RSA) is asking road users to exercise caution while using the roads over the weekend due to the yellow weather warning for high rainfall for the whole of Ireland.
Drivers and motorcycle riders are being warned that during a prolonged dry spell, a build-up of oil and rubber deposit develops on the road.
When the weather breaks, this deposit mixes with rainwater and the road becomes hazardous.
The resulting greasy road surface increases stopping distances and the risk of a skid.
Drivers can get caught out with this change in road conditions so the advice is to slow down and increase braking distance.