This means that according to where you are along the road, your speed limit may change depending on variables such as congestion or other factors.
It will mean the M50 will be Ireland’s first “managed motorway”.
The M50 will be the first road network to have a variety of speed limits depending on where a motorist is driving, as part of the Enhancing Motorway Operation Services (eMOS) programme.
The first strip of the M50 will be subject to variable speed limits within weeks.
Effectively, you may have to drive faster or slower on different parts of the M50, as opposed to one standard speed limit for the road network.
The monitoring system, which will be based on Dublin’s Docklands, will be able to divert traffic off the motorway, clear lanes for emergency services, quickly alter speed limits and also close lanes if the need arises.
It should mean the smoother flow of traffic through the M50 road network.
While the new speed limits will be advisory to begin with, Transport and Environment Minister Eamon Ryan said it is hoped to introduce legislation in the future that would make the speed limits enforceable.
There has been a 40pc increase in traffic on the motorway between 2011 and 2019.
"In 2019, there were approximately 1,200 incidents on the M50, 525 of which were vehicle collisions. With over 400,000 trips per day on the M50, reducing the adverse impact of future traffic growth on safety levels on this key strategic link is hugely important,” he added.
“By enabling motorway operators to react to events as they occur on the network, the programme will allow Transport Infrastructure Ireland (TII) to deliver a more flexible, efficient and dynamic service, enhancing safety for road users, emergency responders and road workers. I’m asking every M50 road user to look out for the signs and to take the necessary action to keep themselves and others safe,” he explained.
The system will be controlled through the implementation of intelligent transport systems (ITS) technology.
Road users will then be advised of the speed limit, diversions, or accidents by a system of close to 100 overhead gantries and slip road signs, as well as hundreds of lane closure and various messaging signs.
Spokesman for TII, Sean O’Neill, said the speed limits could be brought down to 80 and 60 kph, and slower again, depending on the severity of an incident.
A video shown at the launch of the programme showed how incidents on the M50, including truck fires, sudden lane changes, and adverse weather can cause sudden chaos and risks to drivers involved in incidents, drivers arriving suddenly upon an incident, and emergency crews dealing with incidents.
Rear-end collisions account for about 75pc of crashes on the M50.
The eMOS programme is being rolled out in a phased manner, with the first digital signs being switched on between Junction 4 Ballymun and Junction 6 Castleknock in the coming weeks.
Spring 2022 will see the signs switched on between J6 Castleknock and J9 Red Cow.
Summer 2022 will see signs between J9 Red Cow and J12 Firhouse.
Autumn next year will see J12 Firhouse to J14 Sandyford join the scheme.
And Winter 2022/23 will see J14 Sandyford to J17 M11 and J3 M1 to J4 Ballymun completed.
The system is expected to be fully deployed on the M50 by early 2023, according to the Department of Transport.
“In about two weeks time, people will start to notice these new signs popping up between Junction 4 Ballymun and Junction 6 Castleknock. A few months after that you'll notice from Castleknock Junction 6 to Junction 9, the Red Cow interchange,” said Mr O’Neill.
“And then a few months down the line from Junction 9 down to Junction 12 Sandyford, and then after that from Junction 14 with the N11 by the end of the year and into quarter one next year,” he added.
Current traffic figures show that M50 traffic levels have returned to approximately 95pc of the September 2019 pre-pandemic levels.
As part of the €79m programme, nineteen new gantries, 386 lane control signals, 64 variable message signs, 45 CCTV cameras, and 54 slip road signs on the entry points to the M50 are to be introduced to inform drivers of changes to the speed limit in response to incidents and weather conditions.
The Department of Transport have acknowledged that the system of variable speed limits “will require significant public education” to promote awareness of the new system and driver adaptation.
They have also advised that when the first digital signs are activated as part of the programme, they will initially just be in an advisory role to get road users used to adjusting their speeds, and sometimes their route, in relation to the messaging being transmitted from the Intelligent Transport System.
Transport Infrastructure Ireland and the Road Safety Authority are rolling out a public awareness campaign to make drivers aware of the new digital signs on the M50, when they will be switched on, and the importance of following the signs to help keep the M50 safe.