A system which recommends the speed drivers should approach a set of traffic signals to ensure they arrive when lights are green has been shown to significantly reduce vehicle emissions.
The Transport Technology Forum’s SPATULA (Signal Phase and timing for uses; local authorities and automotive) group has analysis which shows GLOSA – Green Light Optimised Speed Advisory – can lead to a cut of more than a quarter in CO2 emissions, and nearly a fifth in NOx from heavy goods vehicles as they leave a motorway.
GLOSA is connected vehicle technology which collects traffic signals timings. It then calculates the right speed to be travelling for drivers to avoid coming to a stop at a red light and presents visually and audibly through an app. If a driver does have to stop at a red light, it gives a countdown to green.