A new Mrieħel underpass meant to mitigate traffic from the nearby business centre is expected to be open to commuters at the end of summer.
Infrastructure Minister Aaron Farrugia on Tuesday visited works on the tunnel, which is expected to be open to vehicles by September.
The entire project is slated for completion by the end of the year.
The two-lane underpass will form part of a new roundabout intersection that is replacing the old traffic lights system at this crossroads between Balzan, Birkirkara and Mrieħel.
Through this tunnel, the main eastbound traffic flows, from Mdina Road, Balzan towards the Mrieħel bypass, will be grade-separated from the other flows converging at this junction.
Launched last year, the underpass project will see a 60-metre subterranean tunnel connecting Mdina Road with the Mriehel Bypass, at the junction next to the Malta Financial Services Authority offices.
In February, Infrastructure Malta completed the excavation of the underpass and started erecting 290 precast concrete panels to form its walls.
On Tuesday, workers lifted in place the first of 16 prestressed concrete beams, each weighing six tonnes, that will support the tunnel roof.
When the tunnel is ready, the agency will build a new roundabout on the road above it, as well as new pedestrian and cycling crossings and landscaped areas.
Minister Farrugia said this investment will continue to minimise bottlenecks and complement the Central Link Project.
Minister evaluating nearby Mrieħel flyover
Meanwhile, Farrugia told Times of Malta that he was still looking at different options for another nearby project, also along the Mrieħel bypass.
Around a kilometre south of the new tunnel, IM plans to install a flyover.
The Qormi council has strongly objected to the original proposal as it would see the take-up of agricultural land adjacent to the bypass.
The authorities are consulting the council on the matter.
Asked for an update on this project, Farrugia said technical experts are drawing up different options and a final decision will be taken shortly.