Traffic lights will stay green for late-running buses under plans being rolled out across the country.

The technology, used by FirstGroup, allows new buses to communicate with "smart" traffic lights which can sense when a bus is approaching and whether it is running on time.

Buses share information about traffic and speed to the cloud, which is then read by the traffic light system which would give a late-running bus priority.

The system would keep a traffic light green for longer to allow a bus through.

On roads without a bus lane the technology works even if the bus is not the first in the queue, giving cars in the same lane priority as well.

The data is also analysed by the bus company and local authority to inform timetabling by working out when traffic is heaviest.

The new technology has been used in Swansea for several years but the company is rolling it out more widely as part of its new contactless payment terminals.

The technology will only work in areas where the local authority gives its assent and also where junctions have the technology to assess traffic levels around them and "talk" to nearby buses.

The system, called Scoot, is created by the Transport Research Laboratory.