News release

From: The Royal Society

Traffic Light Cycles for a Sustainable City

Cities worldwide struggle with traffic congestion, pollution, and car dependency. Surprisingly, traffic light timing, a factor often overlooked, can strongly influence travel choices. Using a new traffic model, we explore the traffic light paradox: giving more green time to cars can actually increase driving times, as extra drivers create congestion that outweighs individual savings. Our simulations show that modest reductions in car-prioritized green time shift commuters toward walking, cycling, and public transport without costly infrastructure changes. These findings reveal that traffic lights are not just flow regulators but powerful tools to promote sustainable urban mobility and healthier, more efficient cities.

Green light go - Reducing the amount of green‑light time for cars at traffic lights could encourage commuters to switch to more sustainable transport. Using grid‑based simulations, researchers found that traffic‑light timing strongly shapes travel times, and commuters adapt to choose the fastest travel option. Small reductions in green light time for cars, alongside more time for buses or pedestrians, proved most effective in encouraging commuters to switch to more sustainable modes of transport.