Motorists are warned to be wary of low blinding sun after 11 collisions were reported in just two hours.
AA Roadwatch said the first day of March was deadly dangerous for morning commuters in Kildare, where the sun affected eastbound drivers on the M4 and M7.
There were 11 crashes between 8am and 10am resulting in traffic delays which stretched for miles.
Nicola Hudson, AA Roadwatch controller, said: "A 50km stretch of the M7 motorway from Portlaoise to Naas was affected by a number of crashes that occurred around 8am, close to Monasterevin.
"Long tailbacks occurred and drivers then encount-ered further delays between the M7/M9 junction and Naas North, where they faced the blinding glare of the low morning sun.
"The M4 was also badly affected, as traffic headed east into the glare, icy conditions on the road enhanced the dazzling effect and gardai were called to deal with eight collisions.
"Traffic between Kilcock and Maynooth slowed to a crawl with a knock-on effect on traffic in both towns."
AA Roadwatch said that over the coming weeks the sun would remain low in the sky at dawn and dusk.
It urged drivers to keep sunglasses in the car, use dipped headlights and clean windscreens inside and out.