Managing speeds – at local, state, and federal levels – is essential to preventing people from being killed and severely injured on our roads. We can manage speeds. And doing so more proactively is key to advancing Vision Zero. While this may seem obvious, the reality is that most communities in the U.S. are not fully leveraging existing, proven speed management strategies. This can change.
Vision Zero rests on a Safe System approach, which recognizes that humans make mistakes, so our transportation systems should be designed in ways that lessen the severity of those inevitable mistakes. Pivotal to this is managing speeds because a key factor in the severity of crashes and injuries depends directly on the velocity – and weight – of the objects involved. This is especially significant for people outside motor vehicles (people walking, biking, rolling), and particularly as vehicle sizes dangerously.
More than 10,000 people lose their lives each year in speed-related crashes in the U.S. We know what works to improve safety on our roadways but, too often, a lack of leadership and action have allowed tens of thousands of lives to be lost each year in preventable crashes.
Fortunately, leadership promoting safety over speed is increasing at the national level. This builds on the National Transportation Safety Board’s (NTSB) landmark 2017 study, Reducing Speeding-Related Crashes Involving Passenger Vehicles, which highlights the deadly problem of speed and calls for specific actions to reduce speed-related deaths and injuries.
In 2021, the U.S. Department of Transportation (USDOT) elevated the importance of focusing on managing speeds for safety in its first-ever National Roadway Safety Strategy (NRSS), stating: “The Department believes it is important to prioritize safety and moving individuals at safe speeds over focusing exclusively on the throughput of motor vehicles.”
Notably, the NRSS encourages communities to take a Safe System approach to managing speeds. This entails moving beyond the traditional approach of focusing mostly on changing the individual behavior of people who are “speeding.” A Safe System approach focuses more on upstream strategies to curb high speeds – steps that roadway designers and policymakers can take at a systemic level, such as re-designing roads and lowering speed limits to encourage safer speeds.
The following strategies build on an upstream, proactive Safe System approach to manage speeds:
Street design is a fundamental strategy to slow speeds and promote safe mobility for all road users. Design techniques such as roundabouts, speed humps, medians, and road diets are proven ways to curb high speeds and improve safety.
We simply cannot educate or enforce our way out of traffic safety problems. Communities must build a foundation of streets, sidewalks, and bikeways that are designed to proactively, physically prioritize safe travel over speed.
As USDOT states in its National Roadway Safety Strategy:
“Design can help to make roads and streets ‘self-enforcing,’ offering drivers contextual encouragement – via lane width, intersection design, pedestrian and bicyclist infrastructure, and other features – to drive at safer speeds.”
Streets with these designs are also referred to as Complete Streets, to accommodate everyone on the road, whether they are walking, bicycling, driving or taking transit. USDOT recommends making Complete Streets “the default approach.”
A Safe System approach calls for setting speed limits based on speeds that are safe for the people using the street – and then designing (or re-designing) the street infrastructure to support that desired speed. Seems simple, right? Unfortunately in the U.S., speed limits are often set at the state level and are outdated and ineffective. Read more about the backwards “85-percentile” approach, and the NTSB and other safety experts recommend replacing it.
Fortunately, more communities are modernizing their approach to setting speed limits. Cities including Boston, Seattle, Charlotte and Madison, Wisconsin – and many others – have lowered their speed limits in recent years as part of their Vision Zero actions to prioritize safety over speed.
As the NRSS states:
“Speed limits frame expectations for drivers and other roadway users, and should be set to provide a safe, consistent, and reasonable speed to protect drivers, other people in motor vehicles, and people walking, biking, and rolling along the roadway. Setting safer speed limits is a critical tool for reducing crashes and injury, and methods for setting speed limits should be customized to the context of the roadway.”
While re-designing roadways to be Complete Streets and lowering speed limits should be primary strategies to manage speeds, interest is also growing in leveraging technology to deter dangerous speeds. As with any approach, technology strategies should be vetted for efficacy and their impacts on equity (more on this below). Following are two technologies:
Speed safety camera programs (or automated speed enforcement) that are thoughtfully designed and monitored – particularly regarding equity considerations – can deter high speeds. Speed safety cameras are shown to reduce roadway fatalities and injuries by 20 to 37 percent, according to the USDOT’s Speed Safety Camera Program Planning and Operations Guide, which provides helpful information for state and local governments on the planning, implementation, and operation of this strategy as part of a broader speed management program.
Benefits of speed safety camera programs can include the following: reducing reliance on armed law enforcement and lessening racial bias and inappropriate police interactions; less strain on enforcement resources; more consistent, around-the-clock deterrence of dangerous speeds than in-person enforcement offers; and others.
The main goal of speed safety cameras should be to deter high speeds – so, a “successful” program, over time, should see a decrease in ticketing because people are, indeed, slowing down. The goal should not be to increase tickets or ticket revenue.
A promising example is New York City, which operates a school zone speed safety camera program. Analysis shows that, at locations where cameras are set up in NYC, speeding during school hours was reduced by 73 percent, and fatalities and injuries have decreased by more than 50 percent. More here.
Equity considerations should be prioritized in any speed management strategy, including camera programs. Equity concerns raised about cameras include potential for the following: over-enforcement in neighborhoods that are predominantly low-income and/or communities of color, recognizing that street design in these neighborhoods is often geared for speed over safety; disproportionate financial burdens on low-income people, given the regressive nature of fines and fees systems; over-dependence on revenue generated by the programs; lessened urgency to address speed problems in more proactive, design-oriented ways; and others.
Speed safety camera programs should be considered short-term strategies to address speed problems, while proactive, longer-lasting measures are put into place; this includes redesigning the roadway to discourage high speeds, lowering speed limits, re-timing signals, and other measures. The end goal should be addressing problems by using upstream strategies, such as self-enforcing road designs and appropriate speed limits and other policies that influence driving behavior – eventually reducing, or even negating altogether, the need for enforcement.
At Vision Zero Network, we recognize and acknowledge important equity concerns related to speed safety cameras and we are working with partners to better understand these and to identify potential solutions.
Intelligent Speed Assistance (ISA) is a promising technology proven to slow speeds. ISA "uses a speed sign-recognition video camera and/or GPS-linked speed limit data to advise drivers of the current speed limit and automatically limit the speed of the vehicle as needed," according to the European Transport Safety Council. ISA works so well that the European Union has mandated that all new vehicles sold in Europe starting in July 2024, must be equipped with ISA.
While the U.S. lags woefully behind in requiring this life-saving technology, some local communities are moving ahead with their own programs. NYC is piloting a first-in-the-nation program to install speed limiters in its city-owned fleet. After six months of ISA in 50 NYC fleet vehicles, preliminary results show that the vehicles traveled within speed limit parameters 99 percent of the time. NYC plans to expand the program fleet-wide. Meanwhile, other cities are stepping up with the Safe Fleets Challenge, led by America Walks.
Advocacy is emerging to leverage speed limiting technology to curb repeat-speed-offenders. For instance, ISA systems could be required in the vehicles of people who have been convicted of multiple dangerous speeding infractions, similar to ignition interlock systems, successfully used in many states, to curb drunk driving amongst repeat offenders.