Project: Assessment of Road Lighting Changes on Energy Usage and Driver Behaviour and Support for EU Numelite Project

Reference: UG480

Last update: 29/08/2007 11:51:40


It has long been established that lit roads reduce the number of night time accidents, but there is little known about the threshold of lighting level where this becomes effective. Various highway authorities are already considering using lower lighting levels. There are also claims and limited research to suggest that lower lighting levels can be used if light which is spectrally closer to white is used. The publication of a new European Standard for road lighting may encourage more highway authorities to light roads in different ways to established practice.

This research is to help determine how far levels can be reduced without losing the safety benefits of lighting. The research will also examine driver comfort on roads with different lighting levels.


This project relates to a European Commission project, NumeLiTe (NUMErical LIght for TEchnology) - an integrated approach to designing high intensity discharge lighting systems.

The key objective of NumeLiTe is to formally prove the feasbility of an optimal and energy efficient outdoor lighting source for road lighting and urban lighting generally. This optimisation will be performed using a numerical software suite especially developed and validated experimentally within the framework of the project.

The research will access data available to TRL as a partner in the NumeLiTe project and conduct additional work, where necessary, to relate this to UK custom and practices. A literature search is to identify inertnational experience of lighting levels and white light.

Studies conducted to complement work on the NumeLiTe project will examine the possible effects of lighting on traffic speeds and flows. traffic characteristics and acident rates are to be monitored and reported at sites where alternative lighting has been used.


TRL Limited
Crowthorne House, Nine Mile Ride, Wokingham, Berkshire, RG40 3GA
+44 (0)1344 773131

Contract details

Cost to the Department: £298,217.00

Actual start date: 28 February 2003

Actual completion date: 31 December 2005


Visual performance under cmh and hps street lighting
Author: G I Crabb, R J Beaumont, D P Steele, P Darley and M H Burtwell
Publication date: 11/05/2006
Source: TRL Limited

Visual Performance Under CMH and HPS Lighting Systems: Numelite Final Project Report
Author: G I Crabb, R J Beaumont, D P Steele, P Darley and M H Burtwell
Publication date: 01/07/2005
Source: TRL Limited