The northbound section of the Molonglo River bridge on the new Majura Parkway is set to be finished within weeks.
Roads ACT director Tony Gill said the last segments of the section of the 250-metre bridge over the Molonglo River were going up over Morshead Drive.
"As this part of the bridge nears completion, a 32-metre-long guiding frame is helping place segments in their final location," he said.
"As each of the bridge segments are finished, they are installed and slowly pushed across the river at about seven centimetres per minute using hydraulic jacks and a steel guiding frame to rest on top of the constructed bridge piers."
A height limit of 4.6 metres is to apply to all vehicles as the bridge goes up, and safety arrangements are in place for workers and motorists.
The $288 million Majura Parkway project, jointly funded by the ACT and federal government, is due to be finished in mid-2016.