Vision Zero and Impaired Driving: Near and Longer-Term Opportunities for Preventing Death and Injuries

Journal article, 2024

Vision Zero involves the use of a systems approach to eliminate fatal and serious injuries from motor vehicle crashes by accommodating basic human limitations that lead to crashes through fundamental behavioral expectations, together with sound vehicle and road design.

Alcohol-related crashes account for a significant proportion of motor vehicle crash death and injury and can be addressed in a safe road transport system. We look at near-term policy and program interventions that are known to motivate drivers to make safe drinking and driving decisions, and possibilities for using technology over the longer term to address risks resulting from driver impairment that is either inadvertent or willful high-risk behavior.

From the Vision Zero perspective,”normal driving” refers to a situation where traffic and road users are operating as desired and planned. A driver in this normal driving envelope operates at a safe speed, wears a seat belt, focuses on the driving task, and is not impaired. A safe system accommodates human errors, mistakes, and misjudgments in the normal driving envelope. However, it may not be capable of compensating for deliberate violations and rule-breaking.

A critical role of behavioral programs and policies is to motivate safe decisions by drivers and other road users and keep them in the normal driving envelope where they can be protected from unintentional errors by a safe system. While much progress has been made in developing and implementing impaired driving policies and programs, much potential remains in the their ability to motivate drivers to meet the fundamental expectations required in a safe system. Examples of behavioral programs and policies that have strong evidence of effectiveness but are underutilized in the U.S. include conducting periodic sobriety checkpoints, lowering the blood alcohol concentration limit for driving, and mandating the use of ignition interlock devices. While the specific interventions may differ, it is likely that the same situation of incomplete implementation of behavioral programs and policies - and consequent unrealized value to a comprehensive safe system - applies to many other nations.

To reach the goal of zero deaths, a comprehensive Vision Zero program needs to address the problem of deliberate risk-taking, which can include driver impairment from alcohol or other causes and extend to dangerous and reckless driving. Advanced safety technologies offer a range of opportunities for this purpose. Cars available today and in the future will have a plethora of sensors that monitor circumstances inside and around the car. These systems can identify whether a driver is in their safe driving envelope and respond with interventions that are appropriate for the severity and nature of the risk. Interventions could range from those that are not perceivable to the driver, such as putting driver assist systems into active mode, to stronger steps such as limiting or preventing vehicle operation.

Zero fatalities or serious injuries in motor vehicle crashes is possible with a systems approach that accommodates human errors and mistakes that occur with the normal driving envelope and incorporates effective responses to deliberate risk-taking outside of this envelope.