USING CONNECTED AUTOMATED VEHICLE TECHNOLOGY TO IMPROVE INTERSECTION SAFETY
By Steven W. Dellenback, Ph.D., PMP
Last year approximately 40,000 people in the United States lost their lives in automobile accidents, an increase of 6 percent from the previous year building on a 7 percent rise the year before that. This upward trend is occurring despite considerable industry focus on safety features such as air bags and vehicle crumple zones. Cars have never been “safer,” and yet traffic fatalities are increasing.
The situation is undoubtedly complex, with many contributing factors. Yet studies have shown driver distraction is to blame for more than 90 percent of accidents in which driver impairment by drugs or alcohol is not a factor. While vehicles are becoming safer to ride in, they are also being outfitted with advanced entertainment and communication devices encouraging drivers to focus their attention inside the vehicle more than on the road ahead.
In order to decrease fatalities on the road, the industry needs to implement safety measures that are as high tech as their entertainment systems, installing “smart” features such as sensors and communication systems that increase a driver’s situational awareness to combat the increased havoc on our roads. And the havoc is sure to increase; as annual total vehicle miles driven in the United States continues to grow — and there’s no indication the rate will be slowing anytime soon — increased congestion and hazards will only create more distractions for drivers.
These trends become particularly acute in urban environments, where approximately 40 percent of crashes occur at intersections. This translates into more than 2 million intersection crashes per year, causing approximately 8,000 fatalities and a significant number of injuries.
Over the past five to ten years, as communities have begun to explore how best to address these challenges, often through “smart cities” initiatives, a number of technology developments have occurred to help improve the situation. Rather than contributing to driver distraction, these promising new technologies lean heavily on computerized sensors and automated data communication systems to provide automated vehicle responses without direct driver input. Some significant technology developments include:
- Automated Vehicle (AV). While this technology has been under development for many years, it has become much more visible to the public lately due to widely publicized efforts by Waymo (Google), Uber, Tesla and others. Many consumer vehicles already have some driver assistance systems to help with braking, parking or staying within a lane. Advanced systems are being developed and tested that would allow complete hands-off driving.
- Connected Vehicles (CV). This technology has been under development for more than ten years. It allows vehicles to communicate with each other so that one vehicle can share its intent with others or communicate with roadside infrastructure, such as traffic signals and sensors that can warn of approaching pedestrians. Within the industry, this is also called V2x (Vehicle To X, with “X” referring to another vehicle, roadside infrastructure or pedestrian). The National Highway Traffic Safety Administration (NHTSA) is in the process of making rules that would require this technology be installed in future vehicles.
- Connected Automated Vehicle (CAV). This blends the technologies of CV and AV so a vehicle has complete situational awareness using data from itself, other vehicles and the surrounding infrastructure.
In urban areas, transportation planners have an even more difficult challenge: improving the safety not just of drivers but also of more vulnerable commuters, such as pedestrians and bicyclists; these users fare the worst in a collision with a multi-thousand-pound vehicle. While efforts focused on enforcement, public awareness strategies and improved infrastructure (e.g. dedicated bicycle lanes) have helped, they have not significantly improved safety for these particular users. Automakers are now implementing vehicle sensors to warn drivers of the presence of pedestrians and bicyclists. However, nearby buildings, other vehicles, and the geometry of some intersection designs often hinder the sensors’ ability to “see” these vulnerable road users.
In these cases, an infrastructure-based sensing approach could provide a more robust environment by utilizing higher-end sensors and processors than a vehicle can currently accommodate. The following graphic presents a concept of how to deploy CAV technology in a centralized point in an intersection to gather data and transmit it to any vehicle equipped with CV technology. A strategically located suite of sensors could “see” down the street and around corners and provide that information to approaching vehicles, pedestrians and bicycles so commuters can make decisions about slowing down or repositioning to improve overall intersection safety.
With the potential NHTSA mandate looming, an increasing number of vehicles will be outfitted with CV technology in years to come, enabling vehicles to communicate with each other and an intelligent infrastructure.
One challenge to reaping the benefits of CAV is that, obviously, vehicles must be equipped with sophisticated technology to utilize the data generated by roadside infrastructure and CAV-capable vehicles. Currently, this technology is expensive. The average cost of a new vehicle is already more than $30,000, and the sensors and computers needed to implement AV technology only increase that cost, potentially making such a vehicle prohibitively expensive. Another factor to consider: recurring operational costs to keep a suite of intersection sensors working. The reality is that the lifecycle of electronics is significantly shorter than that of concrete-and-asphalt infrastructure. Today’s technological solutions, while potentially promising, come with considerable costs.
Undoubtedly, much work remains to be done. Despite dramatic improvements in vehicle safety design, the initiatives behind the drive to reduce traffic fatalities in the United States must become still more proactive and imaginative. To save more lives, engineers need to look beyond airbags and crumple zones. And all stakeholders must instead think “outside the chassis” and adopt automated technologies — in both our vehicles and our infrastructure — that detect traffic hazards and instantly alert drivers, bicyclists and pedestrians. After all, as the saying goes, the safest vehicle in the world is the one that avoids an accident.
Steven W. Dellenback, Ph.D., PMP is the Vice President R&D – Intelligent Systems Division at San Antonio-based Southwest Research Institute.