Calls are being made for better signs at a low bridge after three lorries had near misses in just two days.
Damside Street bridge, a footbridge near the quay was the scene of three incidents last week alone.
One lorry remained under the bridge for some time following the incident, which happened at around 7am last Thursday, but finally managed to pass through without major damage.
A second had a close shave shortly afterwards, and on Friday morning a third lorry driver had to let some air out of his tyres to gain access.
In January a double decker bus had its top ripped off after the driver went under the bridge, and a similar incident damaged a bus in August.
Green Party County Councillor Gina Dowding said: “It’s really important with the increase in incidents that there should be more warnings for high vehicles.
“I know people living on the quay are concerned.
“We need to invest money in more warning signs as its becoming a priority.
“There are signs giving the dimensions but no low bridge sign.
“Something more needs to be done on a basic level.”
Warning signs costing a minimum of £10,000 have been installed at the railway bridge on Torrisholme Road after a number of incidents involving buses there.
But the county council say they have no plans to install such signs on the Damside Street bridge as it is not a priority route.
A spokesperson for Lancashire County Council department said: “We are in talks with the city council about what can be done to make the bridge more visible, for example, chevrons.
“The reason signage has been installed at the railway bridge is its part of the infrastructure and is therefore high priority.”
Andrew Dobson, Lancaster City Council’s chief officer (regeneration and planning), said: “We are currently working with Lancashire County Council to explore ways in which incidents involving vehicles can be reduced.”