The council has been replacing the bulbs over the past two years
Kent's switch-over to low-energy traffic light bulbs to cut carbon emissions is nearly finished, according to the council.
Kent County Council said all of its signal lamps and push-button bulbs would be replaced by September as part of the £1.7m two-year scheme.
It estimates the light-emitting diode units, which have a longer lifespan, will save £150,000 annually.
The council said it would also save about a tonne of carbon dioxide a year.
Kent County councillor Nick Chard added: "The switch from existing halogen lamps will result in substantial financial and environmental savings.
"This is a good example which shows that 'going green' makes sound business sense."