Blog Post

💡 The Impact of Lighting on Road Safety

Using the Vianova Intelligence Platform, the Metropolis of Lyon successfully reduced street lighting on major motorways without compromising safety, achieving a 10% reduction in collisions.

Katell Guillou

‍The Context

The Metropolis of Lyon is a leader in sustainable mobility with 1.4 million inhabitants in a newly combined regional government. As the first French metropolis to join the "Vision Zero" program, Lyon aims to halve accidents by 2030 and achieve zero deaths and injuries by 2050. The city has already implemented several progressive initiatives, including a 30km/h speed limit policy across the city area since 2022 and the ambitious Voies Lyonnaises project, which will provide 250 kilometers of safe cycle lanes by 2026.

‍

Lyon's efforts are also part of the European REALLOCATE program, which supports cities in implementing sustainable road safety strategies under the Vision Zero framework.

‍

‍

The Problem

While prioritizing safety on the road, the city is equally concerned with strategies to decarbonize and reduce its climate impact. Lyon faced the challenge of balancing energy efficiency with road safety when deciding to turn off expressway lights. The city needed to assess if reduced lighting would impact collision rates, particularly concerning vulnerable road users in dark areas where camera visibility was limited.

‍

Could safety be maintained (and possibly even improved) as a result of reducing street lighting on major motorways? The Métropole Grand Lyon implemented an innovative lighting reduction strategy on their peripherique roads (D383/D301) in December 2022. The city reduced its lighting inventory by more than 90%- keeping lights primarily in areas with pedestrian and cyclist density.

‍

This plan also supported Lyon's commitment to reducing energy consumption and combatting light pollution to protect biodiversity, aligning road safety improvements with climate goals.

‍

Technical Approach

Using the Vianova Intelligence Platform (VIP), the city conducted a comprehensive before/after analysis utilizing multiple data sources and methodologies.

Data came from both the existing record of historic collisions (managed in France at the national level) and also connected vehicle data capturing the position and behavior of drivers. This combination of sources allows for the city to be able to evaluate both the occurrence of collisions, but also the occurrence of “near-misses”, evaluated by rapid deceleration.

‍

Pierre Soulard, a project partner, explained: “The use of behavioral data is a way of validating the effects of a decision on road safety more quickly, as the accident database is - fortunately - small, but in fact requires 5 years' hindsight to be deemed representative: this is the added value of your platform in merging data (and all the richer for fire department data).”

‍

This integrated approach enabled Lyon to assess the lighting reduction's impact through multiple complementary safety indicators, providing a holistic view of the intervention's effectiveness over a multi-year time range, including a baseline period prior to the light reduction as well as the new, reduced light test period.

‍

Using Vianova's Intelligence Platform (VIP), the city created a comprehensive before/after Report of collision data on the targeted D383/D301 routes, examining both overall and nighttime (7 PM - 7 AM) incidents.

‍

The Results

Despite the reduction in light visibility, the city was still able to identify a 10% reduction in collisions compared to the prior year, including a 6% reduction during the night hours. Serious and fatal collisions during the night hours halved to 7 for the year in 2023. The lighting change appears to have no negative impact on safety and may have even produced more cautious drivers as a result of the heightened state necessary to drive relying on headlights.

‍

While the results were impressive, the collision dataset represents a small sample size, and therefore needed to be additionally validated by a larger set of indicators. This pattern was replicated in the behavior patterns visible in the connected vehicle data. Importantly, the change in visibility indicated a 22% decrease in harsh braking events between the time periods, as drivers adapted to a road with lower visibility and the need to proceed with caution.

‍

Additionally, the city was able to identify improved compliance with speed limits during nighttime hours, with overspeeding rates decreasing by 8% during the critical window between 8PM and 11PM.

‍

‍

Outcomes

As a result of the combination of collision and behavioral data, Lyon was able to validate and extend its pilot and continue to make progress towards its Vision Zero objectives.

‍

About Vianova

Vianova is the data analytics solution to operate the mobility world. Our platform harnesses the power of connected vehicles and IoT data, to provide actionable insights to plan for safer, greener, and more efficient transportation infrastructures.

‍

From enabling regulation of shared mobility to transforming last-mile deliveries, and mapping road risk hotspots, Vianova serves 150+ cities, fleet operators, and enterprises across the globe to change the way people and goods move.

‍