TERRIFYING: One of highest speeds ever detected on an Irish motorway

Naas Roads Policing Unit detected a vehicle travelling at 242kph on the M4 during wet driving conditions.

The level is more than twice the legal maximum speed limit for that route. 

Gardai used a TRUCam speeding device which detected the vehicle's speed nearly half a kilometre away (403.6km).

The detection was just before midnight.

The motorist may be charged with dangerous driving due to the high level of speed and the poor driving conditions. 

Fixed Charge Penalty Notices were issued to all.