Motorists travelling on the Midlands Highway between the Breadalbane roundabout and Launceston have been urged to allow extra time to make their journey as upgrades continue.
A 900-metre stretch of the northbound road was closed off to traffic on Monday as transition works to the new highway get under way.
Motorists travelling north will be diverted to the southbound lane, which has been converted into two single lanes set at speed restrictions of 80km/h.
Slower speed restrictions may be implemented during working hours.
The altered traffic configuration is expected to remain in place until northbound traffic is switched onto the new highway in November.
For more information visit launcestonairport.com.au