If you pass through Dublin's Port Tunnel in less than three and a half minutes today, you're going to get a fine and penalty points.
New permanent speed cameras came online at midnight last night. They will calculate the average speed for motorists passing through, based on an 80kmph restriction.
Cameras will check your start and finish time on entering and exiting the tunnel.
More than half (58%) of motorists using the tunnel drive over the 80kmph limit, with southbound traffic coming off the motorway going the fastest.
The Port Tunnel cameras are the first of their kind in the country, and may be rolled out elsewhere in the future.