Part-time limits will be put in place outside 33 schools where the highest number of accidents involving children have occurred.
The schools include seven in Bishop Auckland, six in Chester-le-Street, five in Seaham and four in Consett.
Durham Police and Crime Commissioner Ron Hogg said the move would help keep young people safe.
Durham County Council approved the plans at a cabinet meeting on Wednesday.
Only three such zones have been created in the county over the past 10 years, in Seaham, Durham City and Ferryhill.
The authority said 86% of accidents involving children happened within a 1,968ft (600m) radius of a school.
Plans to introduce a 20mph speed limit outside dozens of schools in County Durham have been given the go-ahead.