Drivers who drop rubbish out of their cars are being targetted in a summer crackdown.
In just one month 21 motorists were hit with £80 fines for discarding rubbish in the city.
The aim is to stop the build-up of garbage at roadsides.
It is seen as a crucial part of the Clean Glasgow campaign which was set up to make the city a cleaner, safer and better place.
It also ties in with the Evening Times Streets Ahead campaign, of which Clean Glasgow is a partner, to improve the look and quality of life in the city.
The road litter campaign is widely supported and has seen an increase in the number of incidents being reported and more fixed penalty notices being issued.
A council insider said drivers had been reported by other motorists and pedestrians.
City council leader Gordon Matheson, who is chairman of the Clean Glasgow campaign, said: "Litter thrown from vehicles causes danger and disruption on our roads. It is harmful to the environment, the workers who have to clean the roadside and to the people of our city.
"We urge the public if they see people throwing litter from their vehicles to report it.
"The considerable penalty of £80 should make offenders think twice about their actions."
A city council spokesman said an average of seven bottles and cans can be found along every 100m of major roadside in Scotland.
These can often be the cause of accidents and near collisions as drivers swerve to avoid them.
The public can report people who throw little from their vehicles by phoning the Clean Glasgow hotline on 0300 343 7027.