THE capital's busiest road is almost 30pc busier than during the boom the National Roads Authority (NRA) has revealed.
Almost 120,000 motorists a day are paying the toll on the M50 - a 29pc increase since the road was upgraded in 2010.
The growth in traffic is linked to the economic recovery, but has prompted fears that there could be a return to the gridlock that blighted the ring road.
"It's a significant indicator that economic activity has improved, and with that traffic levels are increasing," a spokesman for the (NRA) said.
"One would assume that this level of traffic will be maintained, but may increase further in the coming years.
"We don't want to go back to the past. The taxpayer spent €1bn upgrading the M50 and it's a critical economic corridor. If it doesn't function, it's detrimental to the entire country."
Last year, the NRA published an analysis of traffic volumes on the motorway finding that "safe operational capacity" was being exceeded at peak times on some sections, including the connection with the M1 to the north, the N4 to Lucan and the West and M7 to Cork and Kildare.
It recommended that five tolling points be introduced across the road, which runs for a total of 45kms.
The decision of additional tolling points could 'split' the fee, which ranges from €2.10 to €3.10, to each of the sections travelled.
This would mean that those who travel the entire length of the motorway would not be penalised.
The NRA said installing multi-point tolling would be a government decision, and it would take three years to install the technology.
The spokesman said it was important to plan now to prevent a return to the gridlock which existed prior to the upgrade.
"It's paramount that we prepare now and look to see what needs to be done to manage the level of service required for the future," he said.
The Department of Transport said there were no plans "at present" to introduce multi- point tolling on the M50, amid concerns that it would push traffic onto local roads.