Topsham and St Loyes in Exeter lose their all-night street lights tonight.
Around 780 lights have been converted to part-time and will go off at 12.30 am, coming on again at 5.30am.
However as with other parts of the city, lighting will stay on all night on the busiest roads and walk-home routes.
The switch-off is saving Devon county council money and reducing carbon emissions.