Almost three out of every five passengers killed on Irish roads this year were aged between 16 and 25, it has been revealed.
The Road Safety Authority (RSA) has urged young people taking lifts over the October bank holiday weekend to ensure they trust the driver.
Noel Brett, RSA chief executive, said: "If out socialising over the weekend, have fun but please don't become a headline in the news because you made bad choices.
"If you intend to take a lift from a friend, be sure you trust his or her driving," he said. "Ask yourself, is the car overcrowded? Has the driver been drinking or taking drugs? If you have any doubts, don't be afraid to speak out and do not put your life in someone else's hands."
Mr Brett has also pleaded with parents to ensure they are supervising their children if they are getting behind the wheel of a car.
Some 173 people have been killed on the country's roads so far this year, compared with 189 for the same period last year. Five people were killed and four seriously injured in traffic crashes over last year's bank holiday weekend.
Transport Minister Noel Dempsey said that although the number of deaths has fallen, there was nothing to "cheer" about.
"One hundred and seventy-three lives have been lost in communities around the country and over 1,000 people have been seriously injured," the minister said. "In the last seven days alone, eight people have been killed in road crashes."
Assistant Garda Commissioner for the Traffic Bureau John Twomey appealed to young male drivers to slow down and take safety seriously. He said: "Young people should think twice before getting into a car with a driver who takes chances. The statistics show that in the event of a serious collision, there is a greater chance that the passengers are at greater risk of death or serious injury."
Meanwhile, a survey of 1,000 people commissioned by QUINN-direct Insurance has found one in three people admitted to being a passenger in a car while the driver was under the influence of drink or drugs. One in five admitted to having driven a car after taking drugs or drink, while almost three-quarters of Irish drivers (71%) had experienced anger or rage while behind the wheel.