Devon rejects lighting for rural roundabout

Road

Devon County Council is to leave a new rural roundabout unlit, saying the environmental benefits of doing so outweigh any  possible road safety benefits of lighting.  

The council has received £2.2m  from the DfT’s Road Safety Fund for improvements to the east-west A3123 in the north of the county. The fund was established to improve conditions on the 50 most dangerous A roads in England identified by the Road Safety Foundation. 

The A3123 had 27 collisions between 2012 and 2016. Devon says three accident clusters exist because of poorly aligned junctions. At one site, Lynton Cross, the council will replace the junction with a four-arm roundabout.

A briefing paper prepared by the council’s road safety team notes that the Highways England’s Design Manual for Roads and Bridges (DMRB) says streetlighting should be provided on all roundabouts.

“The primary application of DMRB is on the high volume high-speed strategic road network,” said officers. “[But] it is often used as a baseline for lower volume rural roads in Devon. Currently there is very little, if any, recent research into the difference between lit and unlit roundabouts in rural areas.”

Devon has studied accident rates at 11 unlit roundabouts elsewhere in the county. “Unlit roundabouts were found to have a slightly elevated darkness collision percentage (33 per cent) compared to a selection of lit roundabouts in Devon (25 per cent) and national collisions at all roundabouts (26 per cent),” said officers. “The number of killed and serious darkness collisions at unlit roundabouts was lower (eight per cent) than at lit (13 per cent) and nationally at rural roundabouts (14 per cent).” 

The paper adds: “Having no street lighting at all on a new rural roundabout where the circumstances suggest that it is an appropriate design would accord with the need to balance road safety and key environmental policies.”  

Dave Black, Devon’s head of planning, transportation and environment, told councillors: “The likelihood of an accident occurring at such a rural roundabout is low and the difference between lit and unlit is small and the severity may be slightly lower.” 

Leaving the roundabout unlit would “minimise the ecological impact on the adjacent English meadow, take account of the dark skies in the rural area, and have minimum ongoing carbon requirements”.