(CNN) Police in India have come up with an ingenious plan to cut noise pollution -- by making vehicles wait longer for traffic lights to go green if they honk their horns too loudly.

Fed up with the din from car horns in their city, Mumbai Police conducted a trial in November and December last year in which decibel meters were connected to traffic light poles.

If the meters registered noise levels of 85 decibels or over, the lights were reset and stayed red for longer.

As in several other Indian cities, traffic lights in Mumbai display countdown timers.

Horn not okay, please!

Find out how the @MumbaiPolice hit the mute button on #Mumbai's reckless honkers. #HonkResponsibly pic.twitter.com/BAGL4iXiPH — Mumbai Police (@MumbaiPolice) January 31, 2020

Pranay Ashok, a police spokesman, told CNN that the experiment took place at a "few important junctions" for 15 minutes a day.

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