Part of the A61 in Chesterfield was closed into the early hours of the morning as a woman threatened to jump from a bridge.
Officers shut the road between the Tesco and Horns Bridge roundabouts at about 10am.
The carriageways were reopened by about 2am.
A Derbyshire police spokesman said: "We got calls from passers-by who saw a woman on the wrong side of a bridge.
"We spoke to her over several hours and thankfully she was brought to safety."
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