The Vision Zero Network was pleased to host a webinar on June 18, 2020 featuring promising speed management efforts in Seattle and Minneapolis. Both cities have prioritized safe speeds in their Vision Zero work, recognizing the critical role speed plays in the frequency and severity of crashes. And both are examples of the growing appetite amongst local communities to modernize their policies and practices to prioritize safety over speed in a lasting, systemic way.
Seattle’s Cost-Effective Approach to Lowering Speeds
Bradley Topol, Seattle’s interim Vision Zero Coordinator, started off by highlighting Seattle’s commitment to reduce speeds citywide for the sake of safety. This includes an initiative to tackle what so many cities are grappling with but few are attending to — lowering inappropriately high speeds on arterial roads.
In fact, Seattle is reducing speed limits on all arterial roads that are currently above 25mph. Since January 2020, Seattle has already reduced speeds on 100 miles of arterial roads, with a plan to do so on a total of 350 miles over the next year-and-a-half. This is part of Seattle Mayor Jenny Durkan’s Vision Zero commitment.
Topol acknowledged that this progress would not have been possible without changes in legislation, as well as political and community support. In 2013, with support from community groups including AARP and community-based organizations, the State Legislature passed a bill giving Washington cities the option to lower residential speed limits to 20mph. In 2016, the Seattle City Council reduced speed limits on all residential streets to 20mph, reduced the default speed on unsigned arterials to 25mph, and started a larger, citywide conversation on the importance of slower, safer speeds, which is now manifesting in lowering all of the arterial speeds.
Do Lower Speed Limits Make a Difference?
So, do these lower speed limits really make a notable difference in speeds and safety? In Seattle’s (and others’) experience, the answer is yes.
Check out the newly released Seattle Dept. of Transportation (DOT) Speed Limits report, which documents their analysis based on 2018 efforts to reduce speed limits on five different arterial roads. After reducing the speed limit from 30mph to 25mph on these arterials, there was a measurable decrease in high speeds, collisions, and injuries. This was accomplished by posting speed signs with the new, lowered speeds and significantly increasing the density of speed limit signs from roughly every 1-to-1.5 miles to every ¼-mile. Topol noted that, in these cases, there were no changes to street design, enforcement, marketing, or retiming signals, showing that even without these additional strategies, simply lowering speed limits can be a consequential first step, especially when resources may not be available for further investments.
The results were impressive: Overall on the five streets, crashes went down by 22% and injuries decreased by 18%. While most individuals reduced their driving speeds by just a few miles per hour, there were significant reductions in high-end speeds -- which are most dangerous -- and significant reductions in the numbers of crashes and, specifically, in injury crashes. Analysis shows a 54% decline in the number of people traveling at more than 40mph.
These experiences of improved safety led the Seattle DOT and decisionmakers to commit to a citywide speed reduction to 25 mph on the remaining 75% of their arterial network. “What we’re seeing right now is that just signage alone, in these cases, made a pretty big impact,” Topol said, pointing to increased awareness of the speed limit and demonstrably reduced speeds and collisions.
Does Sign Density Matter?
Another round of changes showed additional important results. Seattle DOT made changes on two streets located close together. On the first, Greenwood Ave., a commercial corridor, speeds were lowered from 30mph to 25mph and speed limits signs were increased from every 1-t0-1.5miles to ¼-mile spacing. Speeds were effectively reduced by an average of 7%.
On a nearby second corridor, 20th Avenue, a quieter arterial/collector, they took a more traditional engineering approach, setting the speed limit at the "85th percentile" -- an approach common in many places and increasingly questioned and criticized for prioritizing speed over safety. Here, the 85% speed was 30mph; the only change made was increasing the spacing of the speed limits signs were from every 1-t0-1.5miles to ¼-mile spacing, as on Greenwood Ave. In the case of 20th Ave., though, actual travel speeds increased by an average of 4.5-5%.
Topol says the act of increasing sign density along with lowering the speed limit had a real impact on messaging to drivers to slow down, having better safety results. Does this mean that other changes are not important to manage speed, such as street design changes and more promotion, etc? No, says Topol, but it can be an important early step because of its cost-effectiveness. He estimates the cost of lowering speeds to be $4,000-5,000 per mile and something crews can implement quickly versus deeper-dive design changes that may cost 30-times as much and take far longer to implement. This is especially urgent to stem pedestrian injury collisions, which are more common and serious on arterials.
Topol calls lowering speed limits the “most cost-effective thing we can do as a city for safety right now.” He estimates their citywide speed-lowering program will cost just over $1.5M, the cost of a few traffic signals or design changes.
Does it need to take a long time to make these safety changes by lowering speeds? No. In just about five years, Seattle will go from having virtually no arterial streets that were 25mph or less to a city where 90% of the arterials are are at those lower, safer levels.
Benefits of Being Proactive vs Reactive
“Speed limits are a great proactive and systemic solution,” Topol explained. A core principle of Vision Zero is to move from being simply reactive to past problems, as most cities are, to become more predictive and proactive to prevent future problems. Why is this so important? In Seattle, analysis showed that 65% of fatal crashes occurred at locations with no serious or fatal crashes for the prior 10 years. “So, if we’re being reactionary [waiting for 'hot spots' before taking action]...we’re always going to be chasing our tail and we’re never going to get to zero,” explained Topol.
He emphasized that real change happens by putting safety at the forefront of the work, including the way we talk about safety within the transportation agency and other city departments and with the public. “What does it mean,” he asked, “to create a culture of safety around these types of projects? They don’t exist in a bubble. It takes a lot of change. They take a lot of conversations, with the public and with all of your other teams and co-workers and people who approve this work.”
Whenever engaging with the public, Topol suggests always leading with discussions of safety. This means not just using safety as a buzzword but rather to invest in proven treatments and showcase examples from peer cities. It also means measuring changes, sharing data transparently, and understanding and acknowledging the inevitable tradeoffs.
And give the public a megaphone, he suggests. By amplifying the public’s voice and desire for safety, as well as lifting up advocates’ work, you build stronger community support overall. Topol referenced Seattle’s popular “20 is Plenty” signs, which they give free to the public as a way to lift up community voice for change. [Interested in borrowing Seattle’s excellent yard signage template to support your speed management work? They’re happy to share. Check it out.]
He also advises working with the mayor and city councilmembers to keep safety at the focus of their conversations and decisionmaking about transportation issues. At the same time, it is important to foster a culture of safety within the city’s own organizations, which he says includes consistently leading with safety and data; engaging and asking tough questions; understanding people’s concerns; and challenging assumptions, even, sometimes, your own and those of your colleagues.
“It can be hard, and it can be very frustrating,” Topol said, “but if you’re consistent and you keep moving forward with it, you will see change...it just may take some time.”
Learning from Minneapolis
Ethan Fawley, Minneapolis’ Vision Zero Program Coordinator, shared the city’s approach to proactively manage speed for safety. Starting by referencing the murder of George Floyd in Minneapolis and the traumatic impact on his community, he emphasized that issues of traffic safety and questions about the role of enforcement need to fit into a broader conversation around the reality of systemic racism in our country.
As part of its Vision Zero commitment, Minneapolis is lowering speed limits for safety as part of a broader, integrated approach that also includes road design, education, communication, and (potentially) automated speed enforcement as key to making streets safer. Fawley explained that, similar as Seattle, Minneapolis recognizes that higher speeds significantly increase the likelihood of crashes and fatalities and severe injuries: A person hit at 35 mph is three times as likely to die as someone hit at 25 mph (see graph below). This trend is even more severe in low-income neighborhoods, he noted.
State-Level Policy Changes May be Needed
As in Seattle, Minneapolis needed to convince State lawmakers to make changes to local control, in order to move their speed management plans forward. In August 2019, two years after the Minneapolis City Council unanimously adopted a Vision Zero resolution, they and a few other cities proposed State-level legislation to grant locals the authority to determine their own speed limits, if they choose. The State legislation passed and the statute states that speed limit changes must be done “in a consistent and understandable manner… based on the city’s safety, engineering, and traffic analysis.” The legislation also requires “appropriate signs” and “methods to effectively communicate the change to the public.” Speed limits on county and state roads continue to be set by the State.
In coordination with the City of St. Paul, the Minneapolis Public Works Dept. conducted technical speed limit analyses of appropriate speeds for streets, considering their usage and design. (Check out that in-depth Speed Limit Evaluation -- a good model for other cities -- here.)
Since Spring of 2020, both Minneapolis and St. Paul have been implementing their new, locally set, aligned speed limits, including the following:
- 20mph for local, residential streets;
- 25mph larger, arterial, city-owned streets;
- and 30-35mph for a few city-owned streets that feed onto highways.
Both cities are signing their busiest streets and using gateway signs at most entry points to the city, to articulate that the citywide speed limit is 20mph unless otherwise posted. They expect to have changes implemented by the Fall. This is being accompanied by updates to traffic signals and updates to the street design guidelines, including speed management-focused traffic calming such as narrowing street widths and adding traffic circles.
Before this process began, Minneapolis and St. Paul had speed limits of 30 miles per hour on most roads, and both cities adhered to the 85th percentile approach, which generally sets speed limits at the speed at which 85% of drivers travel under free flowing conditions. Citing many findings that this approach is outdated and not suited to best promote safety, Fawley explained that while the 85th percentile may work for freeways, expressways, and rural highways, the reality is that urban roads have far different characteristics, including more diverse land uses and people moving about, including those walking and biking, so setting speeds with the Safe Systems approach is more appropriate.
What’s Next in Minneapolis?
They will be communicating with the public by sharing “20 is Plenty” yard signs, as in Seattle, and emphasizing the message that “slower is safer.” The Public Works Dept. will also be working with community-based groups to spread the message in various languages and with community diversity in mind.
Evaluation will be conducted in 2021 and will be shared with the community before additional, significant changes are considered. Minneapolis is also evaluating the possible use of automated speed enforcement, particularly focused on how to ensure equitable usage and outcomes. Notably, there still remain barriers to lowering speed limits in the city, as some roads are administered by the state or county, and therefore outside of the city’s authority. But, as with a growing number of local communities, Minneapolis is making significant changes to manage speed for safety on its roads.
Thank you to Bradley Topol & Ethan Fawley for sharing their experiences, and to the Seattle & Minneapolis teams for their leadership.