The Disadvantages of Speed Limiters

Speed limiters can help curb excessive speeds, but they also come with downsides: increased speed differentials that can create new safety risks, reduced overtaking and merging capability, driver overreliance on imperfect tech, operational delays and costs for fleets, technical errors from sensors/maps, privacy concerns tied to telematics, and complex liability and enforcement issues. This article explains the main disadvantages for both passenger vehicles and heavy trucks, reflecting recent rollouts of Intelligent Speed Assistance (ISA) in Europe and ongoing policy debates in North America.

Safety trade-offs on real roads

While limiting peak speeds can reduce crash severity, it can also introduce safety drawbacks in mixed traffic, on two-lane roads, and in edge cases where speed briefly aids safety (for example, completing a pass or merging). The points below describe the most commonly cited safety-related disadvantages.

• Speed differentials: When some vehicles are capped and others are not, larger speed gaps can increase tailgating, risky overtakes, and lane-change conflicts, especially on two-lane highways and multi-lane roads with varying flow.
• Passing and merging constraints: A hard limiter can make it harder to complete overtakes on short passing zones or to match speed when merging onto high-speed roads, raising conflict risk.
• Bunching and platooning effects: Limiters can cause groups of slower vehicles to cluster, creating rolling roadblocks that prompt abrupt lane changes behind them.
• Driver overreliance: With ISA or adaptive limiters active, some drivers may pay less attention to signs and conditions, missing construction zones, school areas, or temporary limits if the system does not detect them.
• Emergency maneuvers: In rare scenarios, a brief speed increase can help avoid a collision; strict limiting can remove this option.

Taken together, these effects do not negate the potential benefits of lower speeds, but they show how real-world traffic mixes and road designs can turn a uniform cap into uneven risks.

Operational and economic impacts

Fleets and frequent long-distance drivers may face time, cost, and productivity impacts from speed caps. The following points summarize these operational disadvantages.

• Longer travel times: Even modest caps (e.g., 60–68 mph for heavy trucks) extend trip duration, affecting delivery windows and driver hours-of-service calculations.
• Scheduling and network effects: Slower segments can ripple through logistics networks, necessitating more vehicles or shifts to maintain service levels.
• Fuel and emissions trade-offs: While lower speeds often reduce fuel use, certain engines are most efficient at specific loads and speeds; frequent speed-loss/regain cycles in congested traffic can erode expected savings.
• Driver recruitment and retention: Some drivers view limiters as reducing autonomy or earning potential (where pay is mileage-based), complicating hiring and morale.
• Regional competitiveness: Jurisdictions or fleets with stricter caps may face disadvantages versus peers operating at higher allowed speeds along the same corridors.

These costs vary by route, terrain, and vehicle type, but they can be significant enough to change fleet strategies, staffing, and pricing.

Technical and reliability limitations

Modern speed limiting increasingly relies on Intelligent Speed Assistance that uses cameras and maps to interpret limits. These systems can err, creating practical and safety drawbacks.

• Sign recognition errors: Cameras can misread or miss signs due to weather, occlusion, poor lighting, non-standard signage, or stickers on signs.
• Map inaccuracies and stale data: Digital speed-limit maps may lag behind temporary or recent changes (e.g., work zones), producing incorrect limit enforcement or alerts.
• Contextual ambiguity: Systems can confuse ramp advisory speeds, heavy-vehicle-specific limits, school-zone time windows, and variable speed limits.
• GPS and localization issues: Tunnels, urban canyons, and rural areas can degrade positioning, causing the car to apply the wrong limit.
• Human–machine interface friction: Frequent false alerts or unexpected speed reductions can frustrate drivers, leading to deactivation where allowed or risky workarounds.
• Maintenance and calibration: Cameras, software, and ECUs require updates and upkeep; failures can sideline vehicles or degrade function without obvious warnings.

Because real-world roads are messy, even well-designed ISA and limiter systems can generate edge cases that undermine trust or momentarily impair safe operation.

Legal, enforcement, and privacy concerns

Speed limiters raise questions about liability, compliance, and data use—especially as vehicles become more connected and rules diverge across regions.

• Liability ambiguity: If a limiter or ISA misreads a limit or fails to respond, responsibility for a resulting violation or crash can be contested among driver, employer, and manufacturer.
• Tampering and cybersecurity: Attempts to bypass limiters can create safety hazards and legal exposure; connected systems may add attack surfaces if not secured.
• Cross-border compliance: Differing regulations across countries, states, or provinces complicate fleet compliance and device settings.
• Privacy and data governance: Telematics used to monitor compliance can expose sensitive location and behavior data, raising retention, consent, and access concerns.
• Enforcement complexity: Verifying limiter use or settings at the roadside is non-trivial, and inconsistent enforcement can yield uneven safety and fairness outcomes.

Without clear, harmonized standards and robust data protections, these issues can erode public trust and create uneven playing fields across markets.

Public acceptance and equity considerations

Adoption hinges on how drivers perceive fairness and effectiveness. The following points capture common acceptance hurdles.

• Perceived overreach: Some view mandatory limiters as intrusive, particularly when systems intervene unexpectedly or in low-risk contexts.
• Urban–rural differences: Rural drivers on long, lightly trafficked roads may feel disproportionately burdened by strict caps designed for urban risk profiles.
• Vehicle-type disparities: If heavy trucks are capped more tightly than cars, lane flow and queuing can worsen on grades and two-lane corridors.
• Accessibility implications: For professional drivers, diminished control can be stressful or fatiguing, especially when systems nag or intervene inaccurately.

Perception matters: even modest technical errors or isolated bottlenecks can drive broad skepticism if benefits are not visible and consistent.

Context: where mandates stand

Policy context helps explain why disadvantages are part of an active debate. The European Union has mandated ISA on new vehicle types since 2022 and on all new cars sold since mid-2024, with drivers typically able to override momentarily. In North America, there is no federal ISA mandate for passenger vehicles; some cities use ISA in public fleets. For heavy trucks, Canada’s Ontario and Quebec have long required limiters around 105 km/h (65 mph). In the United States, a federal speed limiter rule for heavy vehicles has been proposed and repeatedly revisited but not finalized as of 2025, leaving fleets to adopt policies voluntarily or meet state-level requirements where they exist.

What can mitigate the downsides?

Although the focus here is on disadvantages, several measures can reduce them in practice.

• Driver override with accountability: Allowing brief, logged overrides helps with merges and passes while discouraging habitual speeding.
• High-quality mapping and updates: Frequent over-the-air map and software updates reduce false limits and missed changes.
• Human-centered design: Clear, predictable alerts and gradual interventions improve acceptance and safety.
• Harmonized policies: Aligning limits and rules across regions reduces compliance friction and odd traffic dynamics at borders.
• Pilot programs and data transparency: Testing on representative routes and publishing results builds trust and informs better settings.

These steps do not eliminate trade-offs, but they can preserve most safety benefits while easing operational pain points and public concerns.

Summary

Speed limiters can reduce extreme speeds and crash severity, but they come with notable drawbacks: risky speed differentials, constrained overtaking and merging, driver overreliance on imperfect ISA tech, operational delays and costs, technical errors from sensors and maps, tampering and cybersecurity risks, privacy and liability questions, and acceptance challenges. The impact varies by road type, vehicle, and policy design. Where limiters are required or adopted, thoughtful override policies, better data and interfaces, and harmonized rules can curb these disadvantages while preserving safety gains.

What are the harmful effects of speed governors?

Some argue that speed governing creates a road hazard when trucks running side by side can’t pass each other. This leads to rolling bottlenecks and traffic congestion, negating some of the theoretical benefits of a reduction in fuel use and emissions.

What are the benefits of removing speed limiters?

Increased Top Speed: The most obvious benefit is the ability to achieve a higher maximum speed. Removing the limiter allows the vehicle to reach its true performance potential, which can be advantageous in certain situations, such as on race tracks or in high-performance driving scenarios.

What are the disadvantages of speed limits?

Potential for Increased Accident Rates with Higher Limits: Raising speed limits in certain areas can lead to higher accident rates. Increased speeds reduce reaction time and increase the severity of impacts, leading to more frequent and more severe accidents.

Is it legal to remove a speed limiter in the US?

Legal and Safety Implications
Speed limiters are in place for a reason—they protect both drivers and pedestrians by enforcing safe driving limits. Legal Issues: Tampering with a speed limiter may violate local laws and regulations.