Police on patrol in the Culmore Road area of Derry noticed a car coming towards them with no lights and found the driver to be over the legal limit.
Danielle Doherty, 41, of Fernabbey Park, admitted driving with excess alcohol on December 11.
The court heard that police saw the vehicle coming towards them with no lights.
They turned and followed the vehicle and the driver was unaware of the police behind her.
Police noted her crossing two lanes without signalling.
When stopped, police noticed the smell of alcohol and an evidential breath test revealed a reading of 60mgs, with 35mgs being the legal limit.
Doherty was disqualified for 12 months and fined £100.
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