A 999 ambulance was stuck behind cars at a red light for roadworks on Wednesday morning.
There were only three cars queuing on Spalding’s Pinchbeck Road but no gap for the ambulance to get by.
An eyewitness motorist said: “Cars from Spalding were driving into West Elloe Avenue, which left drivers going towards town with nowhere to go.
“All the while the ambulance was waiting behind them with blue lights flashing. Why can’t the county council leave a gap for emergency vehicles?
“If there had been 15 vehicles waiting – which is more normal – the ambulance would have had to turn around.”
All three cars went against traffic to let the ambulance through.
Area highways manager Jonathan Pearson said: “Before we carry out major improvements like this, we do let our emergency services colleagues know so they can use an alternative route wherever possible.
“The nature of our work does mean that only one side of the road is available to them, although we do keep this to a minimum and open it up again as soon as it’s safe.”