A city in the US is investing in the first stage of a $10m project to unite hundreds of traffic signals under the control of a government-controlled computerised synchronisation system.

The project in Louisville, Kentucky, involves synchronising 331 traffic signals at four busy commuter roads: Dixie, Shelbyville, Hurstbourne Parkway and Preston Highway.

Initially 35 signals will be synchronised with the remainder connected later as the city secures more funding.

The decision to install the technology is part of a move to reduce air pollution as well as saving travellers time and money, according to the authorities.

The technology will serve up to 80,000 motorists on Dixie and Shelbyville roads and 50,000 motorists on Hurstbourne and Preston roads.

The project will receive $1m from the city, $750,000 from the state and $800,000 in federal congestion mitigation and air quality funds.