The bridge will now open to HGVs from 11pm to 5.30am, increasing the number of journeys that can be made by hauliers during an extra hour and a half.
The new hours were successfully trialled this morning and the structural monitoring installed on the bridge confirmed that the loads were within acceptable ranges.
Transport Minister Derek Mackay said: “Work to restore the bridge to its full capacity is continuing at pace and this is another step towards that goal.
“The HGV trial has been running for more than a week now and our careful monitoring shows that we can now allow more vehicles across the bridge.
“It means that more than ninety per cent of traffic has access to the bridge while the strengthening work is carried-out by our expert team. All indications are that we are on track for the full re-opening soon and we will continue to explore options to allow as many HGVs as possible to use the crossing in the meantime.”
Mark Arndt, chartered engineer and Amey’s account director for the Forth Road Bridge, added: “The HGV trial has gone better than we expected, with many drivers taking advantage of the overnight relaxation on a daily basis. We hope that more will benefit from the extended hours.
“We appreciate that the restrictions are frustrating but they are necessary. Our teams continue to work night and day to complete repair works and get the bridge re-opened as quickly as we can.”