Garda statistics show that 47 people have been killed in road accidents up to yesterday - on average one person a day since the beginning of the year.
That compares to 37 road fatalities for the same period in 2003 - a rise of 27%.
Ten people including a father and son died in road smashes between last Friday and yesterday.
"It's been a bad number of days and a bad start to the year from a safety point of view," said Eddie Shaw, chairman of the National Safety Council (NSC).
In the most recent tragedy, early yesterday morning, a father and son were killed in a four-car pile up near Enfield, Co Meath.
The victims were named as Joseph Jones, aged 59, of Rahan, Edenderry, Co Offaly, and his son, Garry, aged 31, of the same address.
Mr Shaw said that while it was too early to determine a trend in road fatalities it could mark a turnaround from the recent downward slide in death statistics.
"There is a danger that the trend could be reversing. There's an element of complacency there."
The 27% increase over the past six weeks compares to a fall of 10% for the same period in 2003.
Mr Shaw said that in terms of determining trends you needed to look over a four-to-five year period. "There's no doubt that since the Government's National Road Safety Strategy was introduced deaths have fallen by about 28% and serious injuries are down between 30-35%."
The big reduction over the last two years, much of it since the introduction of penalty points, had brought about a change in behaviour among road users, he said.
However, sustaining that change was the problem.
Mr Shaw said that when, as now, there was a sudden rise in road deaths, there needed to be an immediate enforcement response. "We're going to learn a hard lesson this year in that sense, that when you see short-term shifts, we don't have the operational capacity in enforcement terms."
He said the promised 50 additional speed cameras would not be in place until later in the year.
But he said the primary solution to the carnage lay in the hands of drivers.
"We are dependent on people's behaviour; people slowing down, not drinking and driving and wearing seat belts at a higher rate than done in past."