The United States is experiencing a fascinating bifurcation in its approach to speed limits, with major highways pushing maximums to 80 mph or higher in open rural areas, while urban centers are actively reducing limits to 20 or 25 mph in residential zones to curb traffic fatalities and enhance safety for pedestrians and cyclists.
A striking and seemingly contradictory trend is unfolding across American roads. On one hand, states are increasingly green-lighting higher speed limits on expansive rural highways, with some stretches now allowing motorists to travel at 80 mph or even 85 mph. On the other hand, a growing number of cities are actively advocating for and implementing significantly lower speed limits, often as low as 20 mph, in residential and densely populated areas.
This dual evolution reflects a complex interplay of historical precedents, traffic engineering philosophies, public safety concerns, and differing priorities between rural and urban environments. Understanding these contrasting approaches is key to comprehending the future of driving in the U.S.
The High-Speed Highway Reality
The push for faster highway speeds is a continuation of a trend that began nearly three decades ago. In 1974, amidst an oil crisis, President Nixon signed into law a 55 mph National Maximum Speed Limit, primarily to conserve fuel. This federal mandate, while not primarily driven by safety, coincided with a notable 17 percent decrease in traffic deaths between 1973 and 1974. However, the federal government returned authority over speed limits to individual states in 1995, leading to a steady increase in posted maximums on major roadways.
Today, this trend sees no signs of slowing down. At least nine states now permit drivers to legally travel at 80 miles per hour on some highways. Texas, true to its expansive landscape, holds the record for the highest speed limit in the nation, with a segment of State Highway 130 allowing speeds up to 85 mph. Nevada recently raised its limit to 80 mph on a 130-mile stretch of Interstate 80, specifically chosen for its secluded rural desert setting and minimal risk of serious accidents.
Proponents of these higher limits often argue that they simply reflect the actual speeds at which most motorists already drive safely on well-designed, open rural roads. Jay Beeber, executive director for policy at the National Motorists Association, emphasizes that road design is “really the only important factor” in dictating how fast people drive, suggesting that the safest speed is often the one most drivers naturally gravitate toward.
However, safety advocates staunchly oppose this view. The Insurance Institute for Highway Safety (IIHS) maintains a clear stance: “When speed limits go up deaths go up, and when speed limits go down deaths go down,” according to IIHS spokesperson Russ Rader. The IIHS has linked increased speed limits to a significant rise in traffic fatalities, estimating that nearly 37,000 additional people have died in traffic incidents over the last 25 years due to rising speed limits on our nation’s roadways. Their research specifically found that every 5 mph increase to a state’s maximum speed limit ups the chance of fatalities by 8.5% on interstate highways and nearly 3% on other roads, as detailed in an IIHS news update. (IIHS)
The Urban Slow-Down: ’20 is Plenty’
In stark contrast to highways, cities are increasingly adopting a “20 is plenty” philosophy, implementing lower speed limits on residential streets to enhance safety for all road users, particularly pedestrians and cyclists. This shift is driven by disturbing national statistics: nearly 12,000 people died in speeding-related crashes in the United States in 2023, accounting for 29% of all traffic deaths, according to the National Highway Traffic Safety Administration (NHTSA).
Cities like New York, Seattle, and Boston have reported decreases in traffic fatalities after lowering urban speed limits over the past decade. This proactive approach acknowledges that in dense urban environments, the consequences of high-speed collisions are far more severe for vulnerable road users.
Rethinking How Speed Limits Are Set
Historically, speed limits were often set using the “85th percentile rule,” which involved observing free-flowing traffic and setting the limit based on the speed of the 15th fastest driver. However, this practice has faced increasing scrutiny. The National Association of City Transportation Officials (NACTO), in a 2020 report, argued that this method fails to prioritize safety, especially in urban areas, as it was based on research from roads vastly different from today’s bustling city streets.
In a significant development, the Federal Highway Administration’s Manual on Uniform Traffic Control Devices (MUTCD), in its first update in over a decade in 2023, stopped requiring the use of the 85th percentile rule. This change, influenced by NACTO and the National Transportation Safety Board (NTSB), now recommends that if the 85th percentile speed is higher than the existing limit, officials should consider redesigning roads to encourage slower speeds. This could involve interventions such as:
- Adding bike lanes
- Installing speed bumps
- Creating pedestrian islands
Jenny O’Connell, associate director of member programs at NACTO, emphasizes that while simply lowering a sign might not change behavior, designing streets to encourage slower speeds is the most effective solution. Sometimes, lowering the speed limit is a necessary first step to implement more aggressive infrastructure changes like steeper speed bumps.
The Human Cost of Speed
Regardless of whether limits are rising or falling, the data consistently shows the devastating impact of speeding. The National Highway Traffic Safety Administration (NHTSA) reported approximately 43,000 deaths on roads nationwide in 2021, the highest number in sixteen years. This disturbing trend continued into 2023, with speeding identified as a major contributing factor.
The physics of speed are unforgiving. Higher speeds dramatically reduce a driver’s reaction time, making it nearly impossible to avoid sudden hazards. They also significantly increase the force of impact in a collision, leading to more severe injuries and fatalities. Vehicle occupant protection equipment, such as seatbelts and airbags, becomes less effective at higher rates of speed, and the distance a vehicle needs to come to a complete stop increases exponentially.
Driver Behavior and Enforcement Challenges
Experts and law enforcement note that a range of behaviors contribute to speeding, from aggression towards traffic delays and a sense of urgency to reach a destination, to the anonymity drivers feel in their vehicles and a general disregard for traffic laws. Even with advanced assistance technologies in newer vehicles, exceeding speed limits provides little room for error or course correction, especially considering the average age of vehicles in the U.S. is around 12 years old.
The constant challenge is that motorists often view the posted speed limit as a minimum rather than a maximum safe speed. As Wen Hu of the IIHS warns, this can create a dangerous cycle where higher speeds lead to limits being raised to reflect existing driving patterns, which then encourages even faster driving and, consequently, more accidents and fatalities.
Long-Term Implications and the Path Forward
The diverging trends in speed limits highlight a fundamental societal debate: the desire for efficient travel versus the imperative for public safety. While higher highway speeds cater to the demand for quicker commutes and reflect the design capabilities of modern vehicles on open roads, the urban shift towards lower limits underscores a growing commitment to Vision Zero principles, aiming to eliminate traffic fatalities and severe injuries.
The future of speed management will likely involve more nuanced and context-specific approaches. This includes not just adjusting numerical limits, but also implementing sophisticated road designs that inherently guide driver behavior. As communities continue to grapple with rising traffic deaths, the balance between speed and safety will remain a critical point of discussion and legislative action across the nation.
