A lorry wedged on a bridge above a railway has blocked a road in both directions and caused train delays.
Lancashire Police were called to the blockage on Burrow Road, just off the A6 near Lancaster University at about 07:40 BST.
The Great North Rail Project (GNRP) said the lorry, which was stuck for five hours, had caused serious damage and debris had fallen on the tracks.
Network Rail said it had been "entirely avoidable".
Trains between Preston and Lancaster had to run at a slower pace as a result of the crash and there was disruption to services throughout the day.
Network Rail's infrastructure maintenance delivery manager Darren Miller said when "bridge strikes" such as this happen, "it potentially puts passengers at risk and causes huge disruption to journeys".
"We're doing everything we can to organise a full repair of the bridge and reopen Burrow Road as quickly as possible," he added.