The stretch of the busy A16 in Boston is to remain closed until Friday so workmen can repair a huge hole caused by a burst water main.
Anglian Water closed Sibsey Road on the northbound side of Pilgrim Hospital after third-party contractors damaged the pipe.
Water flowing out caused part of the road to collapse, making it unsafe.
People are still able to access the hospital from the Boston side of the road and via the A52.
A spokesman for Anglian Water said: “It has become a really big job as the hole is now the size of a car.
“The estimate for the repairs to be made and the road to be opened is now Friday.”
He added: “Everybody affected is now back on water - except for one customer. Diversions are in place.”
A video of the scene, filmed by The Standard, shows the location of the hole - and traffic being diverted.