A driver on Dublin's M50 was clocked travelling at more than 200kph yesterday - over twice the legal limit.
The vehicle was clocked at 202kph despite the 100kph speed limit on the motorway.
It was just one of 910 vehicles that gardai detected driving at excessive speed as part of National Slow Down Day, which monitored 104,821 drivers.
Another driver was caught speeding at 106kph on the Navan Road in Dublin 15 despite the 60kph limit.
The annual speed check saw gardai mount speed checkpoints at 1,322 locations around the country.
The initiative began at 7am yesterday was set to run until 7am today.
Gardai said the excessive speeds were worrying, given the reduced number of vehicles on the road and the increase in vulnerable road users - such as cyclists and pedestrians - during the pandemic lockdown.
They noted that a driver was recently clocked driving at 119kph, almost double the 60kph speed limit, on the Old Airport Road in Cloghran, north Dublin.
Despite fewer vehicles on the roads since all but essential travel was banned for anyone travelling within a 2km radius of their homes - since extended to 5kms as part of the easing of lockdown measures - there have been six more people killed on Irish roads to date this year compared to last - a total of 57.
Worryingly, almost a third of those killed were pedestrians, representing 30pc of road fatalities.
Superintendent Eddie Golden, from the garda Roads Policing Unit, said some pedestrians were letting down their guard when out walking due to reduced traffic levels, and even venturing on to roadways to avoid other pedestrians on footpaths in order to maintain social distancing.
He said this could be just as deadly as the coronavirus and urged people to be careful when out walking.
"The rules of the road apply to all road users. We would never have walked out on to the road without looking left or right before the pandemic," he told RTE's News At One bulletin yesterday.
"I'm appealing to particularly pedestrians to be aware of that, and also from wearing headphones when they're walking around."
Head of the Roads Policing Bureau Chief Superintendent Paul Cleary said some drivers were taking advantage of reduced traffic in both urban and rural areas to flaunt the law.