Part of the M6 motorway was closed between Saturday night and Sunday morning while a plastic bridge replaced an old bridge due for demolition.
Built using fibre-reinforced polymers, the bridge will be twice as strong but half the weight of the existing bridge, the Highways Agency said.
The M6 was closed between junctions 32 and 34 while the work begins at Mount Pleasant near Garstang, Lancs.
Work was due to begin at 2000 BST on Saturday and end at 1000 BST on Sunday.
Forton Services were also shut during this period.
The same restrictions will apply when the old bridge - built 40 years ago - is demolished on the weekend of 22 to 23 April.