Ten buses serving three second-level schools in the area had been using the car park as a collection point, but the car park has been closed, forcing the buses onto the street.
A spokesperson for Holy Cross Primary School Parents’ and Teachers’ Association said the traffic situation was now chaotic.
The school’s principal teacher, Ursula Coffey, hoped the loss of the car park would focus attention on solving the overall traffic problem in the area.
“What we need is a new traffic system,” she said.
Ms Coffey said it was a question of catering for traffic for relatively short periods in the morning and afternoon as the children came to school and were later collected.
Most of the school traffic is funnelled into the New Road, which provides access to five schools.
School building in Killarney has been focused in this area, which has three second-level schools - St Brendan’s, St Brigid’s and Killarney Community College, and two primary schools - Holy Cross and Presentation Monastery - within a half-mile.
The 130-space New Road car park, known locally as Jimmy the Master’s, has been taken over by the Office of Public Works, and on it will be built Department of Arts, Sport and Tourism offices.
It is expected that 130 civil service jobs will be transferred to Killarney.
But, as a result, more traffic has to park at the New Road, leading to serious congestion prior to the opening of the schools in the morning and their closing in the afternoon.
Local councillors have also warned that the loss of car parking will lead to traffic problems and parking space shortages in other parts of Killarney.
Killarney experiences traffic congestion during the peak tourist season each year.
Arts, Sport and Tourism Minister John O’Donoghue, meanwhile, said design and lay-out plans had been approved for the new Government offices in Killarney. A builder would shortly be appointed and a planning application lodged for the building, he added.
Mr O’Donoghue said while only 11 current staff members in the department had applied for a transfer to Killarney, applications for the 130 posts had exceeded numbers required for most of the grades.
Construction of the building is due to be completed by the end of next year.