A GoSafe speed detection van was set on fire on the old N11 between Arklow and Gorey yesterday evening.
The incident happened at about 7.30pm. An operator was inside the van at the time but escaped injury. The van itself was badly damaged.
Two people wearing balaclavas were seen running from the scene.
Gardaí in Gorey are appealing for anyone who saw anything unusual or suspicious in and around the Citroen Relay van, registration number 11 KK 491, to contact them.
The nvan was parked about 1km south of Arklow on the old N11 Gorey Road.
Gardaí in Gorey can be contacted on 053-9430690.
GoSafe operate mobile safety cameras around the country.
Garda Commissioner Martin Callinan condemned the attack.
"GoSafe are working on a daily basis to assist An Garda Síochána in reducing speed-related collisions and stop loss of life and serious injury on our roads," he said.
"Their work at the side of the country's roads helps to save many in our communities from the tragedy and pain of the loss of family and friends in road collisions. It is so wrong that this vital work directed at making our community safer
for everyone should be the subject of such mindless attack. We are fortunate that no one was injured in last night's incident and I want to condemn it in the strongest terms."
This is not the first attack on a speed detection van. In November, the occupant of a van narrowly escaped when it was set ablaze on the road between Carrickmacross and Dundalk.
Detectives investigating that incident believe it was carried out by a gang with close links to dissident republicans.
In 2009, a garda had a narrow escape when the vehicle in which he was monitoring traffic was set alight in Blarney, Co Cork.
Attacks have also taken place on fixed speed cameras on the N4 outside Kells, and the M1 motorway north of Dublin.