The changes are on Temple Avenue eastbound bridge in Colonial Heights.
Engineers wanted to keep at least one lane open on the busy bridge while repairs were being made to the structure, but later sent out an emergency alert.
“Due to a recent evaluation by the city and our structural consultant today, it was concluded that it is not safe for traffic."
Next, crews shut down both lanes, sending drivers in another direction.
Traffic going eastbound on Temple Avenue will be rerouted to Ellerslie Avenue to Conduit Road.
Crews expect the detours to be in place for at least two weeks.