In transportation safety, one of the most important and well-studied topics is the impact of speed on crash frequency and severity. According to a comprehensive report from the Federal Highway Administration (FHWA), "The Relation Between Speed and Crashes," there is a clear, direct link between vehicle speed and the likelihood and severity of crashes. This report highlights why managing speed limits and encouraging safe driving speeds are vital for improving road safety.

Why Speed Matters on the Road

Speed plays a significant role in both the likelihood and severity of a crash. Higher speeds reduce the time drivers have to react to unexpected events, such as a pedestrian crossing the street or a vehicle stopping abruptly. When a crash does occur at higher speeds, the force of impact is significantly greater, leading to more severe injuries and a higher risk of fatalities.

The report underscores two main issues with excessive speed:

1. Reduced Reaction Time: At higher speeds, drivers have less time to respond to road hazards. This is particularly dangerous in complex driving environments, such as urban areas or intersections, where sudden stops or turns are common.(FHWA)
2. Increased Impact Force: Physics dictates that as speed increases, the force of impact in a collision increases exponentially. This means that crashes at high speeds are far more likely to result in serious injuries or fatalities. (FHWA)

What the Data Says: Speed and Crash Frequency

The FHWA report presents a wealth of data on how speed correlates with crash rates, see figure 2 taken from this report. Studies cited in the report reveal that as speeds increase, so do the frequency and severity of crashes. In particular, roads with higher speed limits tend to see higher crash rates, especially if the road conditions or infrastructure do not support those speeds. For instance, rural roads with high speed limits may lack adequate safety barriers, making crashes more dangerous.

Read more on the study conducted by Rosén et al here:https://nacto.org/docs/usdg/pedestrian_fatality_risk_function_car_impact_speed_rosen.pdf

The data also shows that even minor increases in speed can lead to significant increases in crash risk. A vehicle traveling just 5 miles per hour faster than the surrounding traffic flow is at a much higher risk of being involved in a crash. This statistic supports the importance of setting speed limits that match road conditions and traffic density.

Read more on the Risk of Urban Roads here: https://www.infrastructure.gov.au/sites/default/files/migrated/roads/safety/publications/2001/pdf/Rural_Speed_1.pdf

Speed Limits and Safety: Striking a Balance

While some drivers may view speed limits as arbitrary, they are, in fact, carefully determined to reflect safe driving speeds under typical conditions. Speed limits are set based on a variety of factors, including road design, traffic volume, and historical accident data. Properly enforced speed limits aim to strike a balance between efficient traffic flow and safety.

The report highlights several benefits of adhering to well-set speed limits:

• Improved Reaction Times: Driving within the speed limit allows drivers more time to see and respond to obstacles.
• Reduced Stopping Distances: Vehicles traveling at lower speeds require less time and distance to come to a complete stop.
• Lower Severity of Crashes: When crashes do occur at lower speeds, they are less likely to result in serious injuries or fatalities.

What Can Drivers Do? Tips for Staying Safe

For individual drivers, staying within speed limits is one of the simplest ways to stay safe on the road. Here are a few tips to help drivers manage their speed:

1. Pay Attention to Speed Limit Signs: Always watch for and obey speed limit signs, especially in changing environments like construction zones or school areas.
2. Adjust Speed for Conditions: Bad weather, poor visibility, and heavy traffic are all signs to reduce speed below the posted limit.
3. Stay Alert and Focused: Reducing distractions in the car and staying alert can help drivers stay aware of changing road conditions that might require a slower speed.

The Bottom Line

Speed management is crucial to road safety. By understanding the relationship between speed and crashes, transportation authorities can set effective policies, and drivers can make more informed choices on the road. With evidence-backed speed limits and effective traffic calming measures, communities can reduce crash rates, save lives, and make roads safer for everyone.

Slowing down isn’t just about avoiding a ticket; it’s about creating a safer environment for all road users. So, the next time you’re on the road, remember that reducing speed by just a few miles per hour could make all the difference.

If you have been in a car accident, do not hesitate to call our office and speak with one of personal injury lawyers. 

We have conducted successful trials in relation to the following injuries:

• Traumatic brain injury
• Spinal cord injury
• Fatality
• Burn injury