Tesco is testing infrared queue management technology in nine London Metro stores - and could use it to tell consumers how long they will have to wait before being served.

Over the past year the retailer has rolled out the hi-tech Smartlane system to 700 larger stores, but it has been used only to inform staff and management of individual till performance.

It is understood Tesco is now looking at different ways of using the kit in its Metro stores, where queue structures differ from those in larger supermarkets. One option is using the data to display estimated queuing times for customers to see.

A spokesman for Irisys, which manufactures Smartlane, said: "Metro stores tend to have longer and more snakey queues which, at a first glance, can put customers off.

"However, these queues tend to move quite rapidly and, by publishing an estimated queuing time as opposed to a performance figure, Tesco would be able to manage customer perception much better."

Smartlane uses heat sensors mounted above checkout lanes to detect the number and behaviour of people in the checkout area.

Tesco productivity director Attila Winstanley said the technology was helping store managers to optimise staff deployment.