Sheriffhall LED catseyes

LED road studs linked to traffic lights to guide drivers at complex junction

Image credit: Edinburgh Napier University

Intelligent ‘cat’s eye’ road studs that light up in response to changing traffic lights are to be used for the first time at a motorway junction in north-west England.

Highways England is installing around 170 of the innovative LED road studs as part of a £3m project to improve journeys and safety at Switch Island in Merseyside, where the M57, M58 and three A roads all join together.

This is one of England’s busiest motorway junctions, and is used by over 90,000 vehicles every day.

The LED road studs light up when traffic lights turn green so drivers can clearly see which lane they should follow. Cables under the road surface connect them to traffic lights through a nearby automatic controller unit.

The studs can be visible up to 1,000 metres away – far greater than traditional reflective cat’s eyes – and have been proven to help stop drivers drifting between lanes, reducing the risk of collisions.

The concept was developed by a team at Edinburgh Napier University and transport partners and demonstrated on a busy six-arm spiral-marked roundabout [pictured] on the Edinburgh City Bypass, where accidents were commonplace. The scheme was popular with drivers and won a number of awards.

Highways England has already installed the LED studs at Hindhead Tunnel in Surrey to guide drivers through the tunnel but the Switch Island scheme will be the first time they have been linked to traffic lights at a motorway junction.

Phil Tyrrell, project manager at Highways England, said: “We’re always looking for new ways to further improve journeys and safety for drivers. The innovative light-up road studs, along with the other improvements we’re introducing, will make it much easier to navigate the junction, benefitting the tens of thousands of drivers who travel through it every day.”

Construction work on the Switch Island scheme, which is being funded by the government’s £220m congestion relief programme, is due to start in February and is expected to take around a year to complete.

The scheme is designed to improve the flow of traffic and enhance safety, following 49 collisions at the junction in the past two years. New traffic lights will be installed at a height of over 5 metres – higher than HGVs and double-decker buses – so that drivers approaching the junction can clearly see when the lights are changing.

Other improvements will include changes to the road layout and lane markings, new barriers between carriageways, coloured high-friction surfaces and better signs, as well as creation of a new 400-metre shared cycle path through the junction.

The intelligent cat’s eyes that are being installed at Switch Island were designed by Oxfordshire-based company Clearview Intelligence. Managing director Nick Lanigan said: “The introduction of intelligent road studs, reacting to traffic light changes on a busy roundabout, is a continuation of the traditional cat’s eye legacy but takes advantage of new technology available. The new studs have been proven to reduce lane transgression by over 50 per cent in certain conditions so it’s a great way to help improve safety for all road users.”

Cat’s eyes were invented by Percy Shaw in 1933 after he was driving down a steep winding road in West Yorkshire and noticed his headlights reflect in the eyes of a cat. He realised the potential of improving road safety if he could create a reflecting device that could be fitted to road surfaces and came up with his cat’s eye invention.

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