The Impact of Autonomous Driving on Street Lighting

By CLAUDE ZHU

For over a century, street lighting has served to enhance visibility and create a safer night environment for drivers and pedestrians. Today, autonomous driving is reshaping our transportation, with advanced technologies, safer vehicles, more efficient systems and reliable operation. This will potentially impact the future transportation infrastructure, including street lighting. With the commercialization of AVs, how will the role of the traditional street lighting change?

From rural villages to bustling cities, street lighting plays a crucial role in enhancing road safety. Street lights increase driver visibility, reduce the risk of collisions, and provide pedestrians with a sense of security. Research suggests that proper street lighting can reduce pedestrian crashes by approximately 50%.1

In Australia and New Zealand, street lighting is classified as Category V (Cat. V) and Category P (Cat. P) lighting, focusing on vehicular- and pedestrian-dominated roads, respectively.

Fig. 1 Cat. V lighting concept Graphic courtesy of the author.

The concept of Cat. V lighting is to illuminate the road surface so that the reflected light, in a preferential direction,2 makes the road surface appear bright, against which an object can be seen by the driver as a silhouette, separated from the background, from an advanced warning distance (Figure 1).

Cat. V lighting levels are determined by the traffic volume and speed limit of the roads; the busier the road, the higher the lighting level, with V1 the highest in the lighting standard AS/ NZS 1158 and descending step by step to V4 (New Zealand) or V5 (Australia).

A summary of AS/NZS 1158 for Cat. V road lighting design parameters is shown in Figure 2, excluding the illuminance related components.

Figure 2. Partial light technical parameters for Category V lighting.

Cat. V lighting consumes substantial energy, requires significant maintenance, and contributes significant light pollution and environmental impacts. Its role is expected to be shaken by autonomous driving.

AUTONOMOUS VEHICLE VISION SYSTEM

Autonomous vehicles deploy an array of sensors, including LiDAR (Light Detection and Ranging), radar, cameras, and infrared sensors, to perceive the environment. Unlike human drivers, who rely heavily on light, AVs utilize data from multiple portions of the EM spectrum to detect obstacles, lane markings, and other vehicles, even in low-light conditions (Figure 3).

Figure 3. AV’s vision system 4

• LiDAR uses laser pulses to create detailed 3D maps, enabling AVs to “see” objects regardless of lighting conditions.

• Radar provides information about the speed and position of objects and can operate in poor weather conditions.

• Infrared sensors allow for the detection of heat signatures, such as those from pedestrians and animals, making them ideal for night driving.

• Cameras, while affected by lighting, provide detailed imagery that other sensors may not capture. Many AVs employ cameras with night vision capabilities.

Thanks to the sophisticated systems, AVs are designed to “see” better than human drivers can at night, minimizing the need for traditional street lighting. According to World Health Organisation (WHO) reports, approximately 1.3 million people lose their lives on the world’s roads each year.5 Widespread adoption of autonomous vehicles could lead to a 90% reduction in vehicle crashes.6

POTENTIAL BENEFITS OF REDUCING STREET LIGHTING

As autonomous driving continues to evolve, the required lighting levels on vehicular roads such as arterials and collectors is expected to drop. In the future, when the self-driving systems mature, only minimal lighting will be required for these scenarios.

Together with the smart lighting technologies, substantial energy savings and reduced CO2 emissions could be achieved. Less urban light pollution also helps to restore the natural night sky and preserve the ecological system.

Moreover, municipalities bear high costs for the procurement, installation, and maintenance of street lighting. Autonomous driving could reduce these expenses, freeing up resources for other projects.

CHALLENGES

Cities need to incorporate AV-friendly features, such as dedicated lanes, charging stations, and smart lighting systems that work in sync with AVs.

Vehicular road-based street lighting may not become obsolete in the near future. First, during the transition to fully autonomous driving, non-AVs will still rely on street lighting. It’s unlikely that all vehicles will be autonomous in the short term, especially in rural or economically disadvantaged areas where the transition could take decades.

Second, while AV sensors are intelligent, they are not infallible. Adverse weather conditions like heavy fog, snow, and rain can impair sensors. Street lighting could offer an additional layer of safety in case of emergency.

Therefore, urban planners are likely to maintain some level of street lighting to ensure safety and accessibility for all residents for the foreseeable future.

Figure 4. Night sky at Lake Tekapo, New Zealand Credit: Aoraki Mackenzie, International Dark Sky Reserve

SMART LIGHTING

Harnessing the power of dimmable LED lights, motion sensors, and connectivity features, smart lighting systems could reduce light levels in areas where AVs are prevalent but highlight key areas when human drivers or pedestrians are present.

In addition, AVs could communicate with smart streetlights to request lighting as needed, ensuring that the streets are only lit when necessary. Hybrid solutions allow for a gradual transition from traditional street lighting to more AV-compatible systems, ensuring safety and efficiency for all road users.

CONCLUSION

While autonomous vehicles have the potential to operate effectively without street lighting, it’s unlikely that vehicular road-based lighting will become entirely redundant. Pedestrian safety, non-autonomous vehicles, and sensor limitations suggest that some form of street lighting will remain essential. However, smart lighting offers a promising compromise, enabling municipalities to reduce energy consumption and light pollution while maintaining safety for all road users.

In the future, autonomous driving may inspire a re-evaluation of street lighting’s role in urban infrastructure, but it is unlikely to eliminate the need for it altogether.

As technologies evolve, cities can explore innovative lighting solutions that balance the needs of both AVs and traditional road users, paving the way for safer, more efficient, and environmentally friendly urban spaces.■

REFERENCES

1. Rea, M. et al. (2009). ‘Review of the Safety Benefits and Other Effects of Roadway Lighting’. https://onlinepubs.trb.org/ onlinepubs/nchrp/docs/NCHRP05-19_LitReview.pdf

2. Julian, W. (1999). Lighting: Basic Concepts, University of Sydney.

3. ‘Lighting for Roads and Public Spaces-Part 1.1: Vehicular traffic (Category V) lighting-performance and design requirements’, Australian/New Zealand Standard, AS/NZS 1158.1.1:2005, Table 2.2

4. General Motors (2018). ‘Self-driving Safety Report’. https:// www.gm.com/content/dam/company/docs/us/en/gmcom/ gmsafetyreport.pdf

5. Martin J (2013). ‘Self-driving Cars’, UK.

6. MCCA Global Tec Forum (2018). ‘Autonomous Vehicles: Navigating the Legal and Regulatory Issues of a Driverless World’. https://mcca. com/wp-content/uploads/2018/04/Autonomous-Vehicles.pdf

Cover Photo: Photo Credit: Adobe Stock-Chingiz