Drivers are being urged to slow down as the evenings get shorter.
Gardaí have issued the warning and are also driving home the message that it is totally unacceptable to drink or take drugs and drive.
It is after new laws came in that will ensure that all drink drivers will be put off the roads for three months.
Chief Superintendent Finbarr Murphy says officers will be checking for drink-driving this weekend.
"Last week, we arrested 195 people for drink and drug-related driving," said Chief Superintendent Murphy.
"Again, we will be out this weekend and right through the rest of the year in order to enforce this to its fullest measure and reduce road deaths.
"So far this year there have been 120 people killed on our roads."
Announcing the new provisions of the Road Traffic Act, Transport Minister Shane Ross said the measures were a "significant step in clamping down on the scourge of drink driving".
"There are few more irresponsible and dangerous things people can do in everyday life than drink and drive," he said.
"It was always wrong to give people the mild slap on the wrist of three penalty points for such potentially lethal behaviour, and it is a great satisfaction to know that in future people who behave this way will face a disqualification from driving for three months."