A Case Study on Managing Speed for Safety
Speed-related fatalities and injuries have reached alarming numbers, with a recent national study finding that more than 10,000 deaths each year in the U.S. are related to speeding. That’s an estimated 27 lives lost each day – children, parents, grandparents, friends – all deaths that could and should be prevented.
Standing in the way of preventing these human tragedies are outdated approaches and standards that have failed to preserve safety for people moving on our roadways, sidewalks, and bikeways. This is particularly problematic in many states, where inertia or resistance to making difficult political decisions at the state policy level ties the hands of local communities who want to improve their own speed management practices. Download the PDF here.
Vision Zero Motivates Change
(Download a PDF here.)
Fortunately, many local leaders are stepping up to modernize and improve the way they manage speed. As part of their Vision Zero commitments, these communities are taking a more upstream approach to speed management, moving beyond the traditional methods of education and enforcement campaigns in order to focus more effectively on addressing the underlying systems, policies, and the built environment that influence individual behavior. This means understanding that we need to do more than post billboard campaigns imploring people to “slow down” and focus greater public and policy attention on how we design streets and neighborhoods, how we set speeds, and how we communicate and socialize expectations for behavior.
Vision Zero is based on the Safe Systems approach, which recognizes that people will make mistakes, 
so we call on system designers and policymakers to design transportation systems in which those inevitable mistakes do not end in death or severe injuries. And a cornerstone to succeeding in this approach is managing speed. Because, in the end, it’s speed that kills.
It is an easy-to-understand fact that a person’s chances of surviving a crash decrease dramatically if they are involved in a high-speed versus a low-speed crash, especially if that person is hit while walking or biking, or if they are more physically vulnerable, including the elderly and the young. But for too long, this simple fact has been undervalued or ignored, often due to political or practical challenges.
Fortunately, this is changing, as local leaders recognize that we can manage speeds to preserve life.
Taming Speed for Safety in Portland
Portland, Oregon is one of the communities taking a leadership role in managing speed, developing a multi-layered strategy focused on upstream policy and design changes to encourage safe speeds that result in safer conditions for all roadway users.
In this Case Study, we highlight promising efforts in Portland, Oregon to incorporate a Safe Systems approach in its speed management efforts. In particular, we highlight Portland’s Bureau of Transportation efforts to:
- Analyze and determine how speed relates to severe injury and fatal crashes early on in its Vision Zero initiative,
- Work with the Oregon Department of Transportation to develop alternatives to the 85th percentile practice, and gain flexibility to use Safe Systems alternatives to set appropriate speed limits for safety,
- Prioritize street design changes on streets where crashes and speeding are more prevalent, such as the High Crash Network and in low-income communities and communities of color, and
- Include automated enforcement as part of its speed management program, specifically to pilot safety cameras on select streets where they are needed most.
Focus on Need to Modernize Speed-Setting Standards
This Case Study focuses the greatest attention on Portland’s promising work to move beyond the traditional 85th percentile speed setting methodology, as this is one of the issues that most stymies many local communities aiming to modernize and improve their speed management work.
The 2017 speed study by the National Transportation Safety Board (NTSB) found the most common practice for setting speeds, the 85th percentile “rule,” which most states stand stubbornly by, is based on dated research that is less relevant to urban environments, and results in unintended consequences of speed escalation and reduced safety. In fact, the NTSB study recommends a Safe Systems approach to setting speed limits, which factors in crash history, land use, and the presence of people walking and bicycling.
This is the approach Portland is leading on now, in the name of Vision Zero and safe mobility for all. We believe their important work can be a model to other communities aiming to update their policies and practices to put safety first.
We hope you’ll enjoy and learn from this Case Study. Download a PDF here, and to hear more about Portland’s experiences, watch this Vision Zero Network webinar.