The nation’s airports will need a drastic increase in infrastructure investment in order to cater for the projected booms in passenger number, a new report from the Australian Competition and Consumer Commission (ACCC) has found.

The annual Airport Monitoring Report for 2011-12 has found that the major airports of Adelaide, Brisbane, Melbourne, Perth and Sydney have all slumped in quality of service, while still remaining highly profitable.

The report concluded that a combination of strong domestic demand, fuelled by fly-in fly-out workers,  increase international passenger volumes and higher costs charged for services had contributed to higher revenues for all major airports, with the exception of Adelaide.

“It is apparent that continued growth in passenger numbers at most airports is placing pressure on existing aeronautical infrastructure, contributing to lower service standards. More investment is required to avoid excessive congestion, and ensure that the needs of Australia’s travellers can be adequately accommodated,” ACCC’s Chairman Rod Sims said.

Mr Sims said that this year’s report found evidence of growing congestion, pointing to the growing percentage of flights that are not leaving on time.

The report concluded that targeted investment in infrastructure could avert the growing problem of congestion in the nation’s major airports.

This year, Sydney took out the ignominious title of the nation’s most congested airport, with the general approval rating slipping from ‘satisfactory’ to ‘poor’ in 2011-12.

Brisbane Airport remains the airport with the highest ranking for overall quality of service among monitored airports, in 2011-12 airlines lowered their rating of runway availability from “good” to “poor”.

In what will come as little surprise to Victorian’s, Melbourne recorded the highest revenue from parking services and related parking activities, while the overall quality of airport’s service fell.