Traffic on the Ipswich Motorway yesterday.
One lane was closed, causing long delays.
A switch from an old section to a new part of the motorway at Riverview struck disaster about 6am when crews realised the stretch of road linking the old route to the new motorway lanes was unsafe.
The Department of Transport and Main Roads later told The Queensland Times that engineers determined the damage had been caused by overnight rain, although only 10mm of rain was recorded at the nearest weather station at Amberley.
The department declined to apologise for ensuring the link to the new motorway was roadworthy before allowing traffic to use it but thanked motorists for their patience during the delays.
The roadworks to repair the lane caused traffic to back up all the way to the Centenary Highway towards Brisbane and the Stapylton Road exit on the Logan Motorway.
The monster jam caused 612 ABC Brisbane presenter Madonna King and many of her guests lined up for her Ipswich broadcast to be late and also affected Ipswich's courts.
Court one, Ipswich's main arrest court, opened half an hour late as the rostered magistrate was affected by the traffic jam.
Magistrate Virginia Sturgess opened the court at 9.30am until Magistrate Michael Quinn arrived to take over, frustrated by the two-and-a-half hour drive he had endured from Brisbane.
Traffic in the eastbound lanes heading out of Ipswich was also hampered yesterday afternoon by a traffic crash under Mine Street overpass about 6pm.
A Transport and Main Roads spokesperson said they would be moving "heaven and earth" to have the lane fixed in time to re-open this morning.
"The repairs do not affect the new motorway and will be completed tonight (Wednesday), weather permitting," the spokesman said in a statement.
The authority expected two lanes of traffic would be open at normal speeds on the new motorway for the morning peak.
The closure of the Formation St on-ramp on the Ipswich Motorway westbound at Wacol westbound has also been blamed as a contributing factor to the recent traffic delays.