The Dublin Port Tunnel opened for use by cars, buses and motorcycles at 6am this morning.
A toll applies to all users including taxis but excluding Heavy Good Vehicles and coaches with over 25 seats.
A Northbound trip from Monday to Friday, between 6am and 4pm, will cost users €6.
It is twice that to travel Southbound on a weekday between the hours of 6am and 10am.
Around 6,000 trucks have been using the tunnel everyday since it opened to HGVs in December of last year.
The maximum speed limit within the tunnel is 80km/h.
Drivers are advised to dip their headlines and to keep a safe distance from those in front of them.
The first big test for the effectiveness of the Dublin Port Tunnel on easing weekday rush hour traffic will begin tomorrow.