Gardai are to crack down on vehicles with defective lights, and motorists using fog lights when there's no fog.
A €60 on the spot fine will be slapped on motorists driving cars with broken lights stopped at checkpoints across the country.
This follows surveys which have shown an increased number of such vehicles on the road, and a fifth of cars failing the NCT because of defective, missing, or broken lights.
The crackdown is being run under the banner 'Light Up'.