In 2019, we ran a competition seeking innovative ideas for developing digital roads and improving air quality.
One winning entry explored technology known as Green Light Optimised Speed Advisory (GLOSA).
GLOSA gives drivers speed information that helps them to pass through green traffic lights. This reduces the number of vehicle stop-starts at signalised motorway junctions and can, in turn, improve air quality.
We worked with Amey to develop and trial the in-vehicle technology. Other partners involved included:
We ran the trial using traffic lights on three slip roads in the north west.
We used a portable emission measurement system to capture real driving emissions data on these short routes.
We used two vehicles, a light commercial vehicle and a heavy goods vehicle (HGV), completing around 400 trips for the trial. We generated comparable data by doing a number of runs on the same slip road.
Initial analysis of results suggests that vehicle CO2 emissions were reduced by as much as 27% by minimising unnecessary speed changes.
This also led to a 17% reduction in the level of nitrogen oxide (NOx). The most promising results were from HGV testing.
We are now testing the technology with a different type of traffic signal control system. If testing is successful, we will start working on a GLOSA Strategy for potential roll-out in our third road period (RIS3 2025-2030).
Connected and autonomous vehicle
Energy and environment