Connected and Automated Vehicles


Safety is the priority at WisDOT. The department is investigating how connected and automated vehicles can bring a new level of safety to transportation.

  • Working with partners throughout Wisconsin to identify and resolve safety issues
  • Gathering, analyzing, and reporting data on traffic crashes and injuries, and then using that data to inform policies, investments, and enforcement of safe operations on state highways and Interstates
  • Managing state and federal funds to build safer infrastructure on our roads, rail system, and at our state’s airports
  • Conducting public outreach and education campaigns, including those focused on pedestrian and bicyclist safety
  • WisDOT: Safety first

The Safe System approach to safety differs from conventional safety practice by seeking safety through a more aggressive use of vehicle or roadway design and operational changes as well as behavioral changes – and by fully integrating the needs of all users (pedestrians, bicyclists, older, younger, disabled, etc.) of the transportation system. The Safe System approach is part of the US Department of Transportation’s National Roadway Safety Strategy. Connected and automated vehicle technologies have the potential to provide solutions to address several of these principles such as; safer vehicles that react to emergencies, identifying road design improvements, improving traffic operations management.

Safe System principles:

  • Safe People – People make mistakes and are vulnerable: encourage responsible behaviors, apply policies equitably, and engage stakeholders
  • Safe Vehicles – Utilize systems and technologies that minimize impacts: air bags and safety restraints, commercial vehicle technologies that improve safety, and alcohol and distracted driving detection systems
  • Safe Speeds – Develop outreach, aggressive driving campaigns, and enforcement, examine speed setting limits, and incorporate roadway and infrastructure factors that can deter speeding
  • Safe Roads – Prioritize designs that account for vulnerable road users, encourage situational awareness and allowances for human mistakes
  • Post-Crash Care – Ensure quick and safe access to, on, and from the crash scene to improve access to critical care, develop advanced traffic incident management training

A widely shared 2015 NHTSA analysis found that 94% of crashes are a result of human error (Table 2). But many elements contribute to create the conditions of a crash, and this statistic cannot be misconstrued to identify the cause of a crash as solely the fault of the driver. The Safe System approach to safety can address other contributors to a crash such as road design, traffic operations, vehicle design, and more. Where human error did contribute, automated warning and control systems can help to mitigate these errors. Communication systems, redundant sensor and control systems with better perception, reaction time and attention spans than humans have already shown to reduce crashes. Supporting the research and integration of these systems is one of WisDOT’s priorities.

Driver-Related Critical Reasons for Crash

Critical Reason Percentage Estimate*
Recognition Error41%
Decision Error33%
Performance Error11%
Non-Performance Error (sleep, etc.)7%
*Based on 94% of the NMVCCS crashes. Data Source:

Generally, self-driving cars can be safer than human drivers. Unlike humans, many have 360-degree sensors that are active constantly, and can be effective at eliminating most accidents caused by human error. Automated Driving Assist Systems (ADAS) systems never get tired, do not text while driving, do not drive under the influence, and can reduce the number of crashes caused by human error.

However, driverless cars can still trip up under certain situations. Bad weather can impair the car’s sensors and systems, making them more prone to errors. Driverless cars are still learning to navigate the chaos of inner-city traffic, especially in large megacities like New York, Boston, and others. Additionally, driverless cars perform worse in edge cases (extreme or highly improbable situations that are not normally expected in the real world).

Most safety regulations for automated vehicles are not mandatory, and regulators are unsure of how to standardize laws across states. Computers lack intuition and instinct which is common in human beings. This can affect their response in some situations. Thus, self-driving cars require further engineering to improve their response to complex situations – particularly edge cases. In many cases the sensor systems can perceive and act faster than humans in certain operation design domains. We may still need many years of improvements before they can be truly termed ‘safer’ than humans in the majority of driving conditions.

Driverless taxis and trucks have logged millions of miles on the road with and without drivers, with billions of miles in verified simulations. When operated appropriately in accordance with the vehicle’s operational design domain (ODD), they have fewer crashes than humans. Results from the first set of data from NHTSA’s standing general order show that the vast majority of crashes involving an ADS-equipped vehicle were from the vehicle being hit from the rear. Summary Report: Standing General Order on Crash Reporting for Automated Driving Systems.

National Highway Transportation Safety Administration (NHTSA) Self-Certification

The National Highway Transportation Safety Administration (NHTSA) sets the safety standards for vehicles. Manufacturers self-certify that their vehicles comply with those standards with clarification from NHTSA if needed. NHTSA monitors and investigates the safety records of vehicles used on the public roadways and will issue a safety recall of those vehicles if necessary.

Voluntary Safety Self-Assessment | NHTSA

NHTSA issued the Standing General Order in June 2021(the General Order) requiring identified manufacturers and operators to report to the agency certain crashes involving vehicles equipped with automated driving systems or SAE Level 2 advanced driver assistance systems. If NHTSA finds a safety defect, it will take action to ensure that unsafe vehicles are taken off public roads or remedied, as appropriate. The Standing General Order is the first wide-ranging effort to document system disengagements and crashes of automated vehicles that are being tested or deployed across the country. Data collected will help inform federal and state policy on testing and deployment.

Standing General Order for Crash Reporting

Summary Report: Standing General Order on Crash Reporting for Level 2 Advanced Driver Assistance Systems

Safety features available in current vehicles

Automated technology now available in many vehicles on the road is already improving safety. Vehicle safety features such as Blind spot warnings, Adaptive cruise control, Lane keep assist, Emergency braking are already making new cars safer than the previous generation.

  • See the General CAV Technology section for more information and Safety Related Resources at the end of this section

Infrastructure and vehicles that can talk to each other can help prevent certain crashes; Wrong-way driver detection and Red-light running detection will be able to warn other vehicles when a roadway or intersection are not safe to enter, Work zone location information and the statewide Traffic Management Center will be able to provide up-to-date roadway and traffic conditions to connected or automated vehicles.

WisDOT is working with researchers, external advisory committees, non-driver groups and other state DOTs to investigate how connected or automated technologies can help reduce fatalities and injuries for vulnerable road users. Some of these automated technologies are in new cars today, some are emerging. Many connected technology studies and pilot programs are going on around the country with WisDOT participating in some of those projects and monitoring others. LiDAR, RADAR, cameras, and ultrasonic sensors that are always active can dramatically improve the awareness of vulnerable road users in challenging weather and light conditions.

Technologies with potential to affect vulnerable road users:

  • Blind spot detection and warnings – can detect hard-to-see motorcycles and warn drivers of their presence
  • Red light running detection – can warn drivers or pedestrians of vehicles that are about to enter an intersection against the right-of-way
  • Work zone location – can communicate static or mobile work zones to automated vehicles or to navigation systems to warn drivers
  • Obstacle Detection – sensors detect objects in the roadway including people and bicycles
  • Pedestrian Detection – system can detect and identify pedestrians and estimate their speed and trajectory to plot a path with a safe buffer space
  • Bicycle Detection - system can detect and identify bicycles and estimate their speed and trajectory to plot a path with a safe buffer space
  • Automatic Emergency Braking – detects objects and combined with vehicle speed can apply brakes if speed exceeds normal braking window
  • Lane centering assist - can monitor lane lines and nudge vehicle to stay within lanes