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What is Speeding?

Speeding is defined as driving over the posted legal speed limit or driving too fast for
existing conditions, such as the weather and the environment [1]. Speeding is
responsible for nearly one third of all road fatalities in the US, with over 13,000 lives
lost annually in speed-related crashes [2].
In Nevada, between 2018 and 2021, there were 759,338 non-adjudicated speeding
citations issued, accounting for approximately 53.3% of all citations [3]. Additionally,
from 2014 to 2023, Nevada (NV) recorded 1,026 speeding-related fatalities,
representing 30.1% of all traffic fatalities in NV during that period [4].

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Why is Speeding Dangerous?

As Figure 1 depicts, speeding significantly increases the risk of crash injuries and
fatalities by:

• Increasing the distance required for a vehicle to stop. Higher speeds reduce
  the driver’s available reaction time to respond to road hazards, such as other
  vehicles, pedestrians, and obstacles.
• Extending the braking distance after the brakes are applied, requiring more
  distance for the vehicle to come to a complete stop.
• Increasing crash impact force [5].

Figure 1: Higher Speeds Increase a Driver’s Reaction Distance and Braking Distance [6]

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Speed and Injury Severity

Figure 2: Kinetic Energy Transfer During Vehicle Collision

Higher speeds are strongly associated with an increased risk of crashes, as well as more severe injuries, greater vehicle damage, and a higher likelihood of fatalities [7, 8]. The reason lies in what is known as kinetic energy, the energy a vehicle has because it is moving. It is measured by joules and increases exponentially with speed. If a car increases its speed, its Kinetic Energy also increases exponentially [7, 9] [Figure 2]. In a crash, kinetic energy is transferred between the vehicle objects, or vulnerable road users such as pedestrians, bicyclists, etc., leading to more severe injuries or a higher likelihood of death: 

• Severe injury to vehicle occupants: The forces exerted on the body can cause significant trauma, including traumatic brain injuries, internal bleeding, and fractures of bones [10]. While seatbelts and airbags are designed to reduce injuries, their effectiveness becomes limited at high speeds when the force of impact can exceed what these safety features can absorb [11]. 
• Increase risk for vulnerable road users: Pedestrians and cyclists have little or no protection against high-speed impacts. A pedestrian struck by a vehicle traveling at 50mph has only a 25% chance of survival. At 60 mph, the likelihood of survival decreases to approximately 8%, and continues to decline as speed increases [Figure 3].

Figure 3. Risk of Pedestrian Death in Relation to Impact Speed [12] 

For more information on Nevada’s speed restrictions, visit the Nevada Revised Statutes (NRS)

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Key Takeaways

• Higher Speed = Greater Impact – The more kinetic energy in a crash, the more severe the injuries. 
• Speed Reduction Saves Lives – Lower speeds mean less energy transfer, reducing harm to drivers, passengers, and pedestrians, reducing the severity of injury and the probability of death.
• Safe Driving Habits Matter – Maintain a safe distance, follow traffic rules, and drive at appropriate speeds to minimize collision risks.
• Prevention starts with awareness- Understanding kinetic energy helps in designing better traffic safety strategies to manage crash impact forces.

Safe speeds save lives. Manage kinetic energy, prevent severe crashes!

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References

1. Federal Highway Administration. Speed Management: A Manual for Local Rural Road 
   Owners. n.d. Accessed from: https://highways.dot.gov/sites/fhwa.dot.gov/files/2022-06/speedmanagementguide.pdf
2. Federal Highway Administration. Factors Influencing Operating Speeds and Safety on Rural and Suburban Road. (2015).  https://www.fhwa.dot.gov/publications/research/safety/15030/15030.pdf 
3. Stricker, E., Reyes, A., Charupoom, M., Bacani, N., & Kuhls, D. Nevada non adjudicated speeding citations; 2022. Updated December 30, 2022. Accessed from: https://trafficsafety.sites.unlv.edu/category/newsletters/volume-11/page/5/ 
4. Nevada Advisory Committee on Traffic Safety (NVACTS) 2024 Annual Report. https://zerofatalitiesnv.com/app/uploads/2024/12/2024-NVACTS-Annual-Report-1.pdf 
5. National Highway Traffic Safety Administration. Speeding. n.d. Accessed February 25, 2025. https://www.nhtsa.gov/risky-driving/speeding 
6. Figure 1. National Highway Traffic Safety Administration. Higher speeds increase a driver’s reaction time and braking distance. Image. Vision Zero Network. Published 2015. Accessed February 28, 2025. https://visionzeronetwork.org/resources/safety%20over-speed/
7. Institute of Road Safety Research. The Relation Between Speed and Crashes Factsheet. 2012. 
   https://fietsberaad.nl/CROWFietsberaad/media/Kennis/Bestanden/FS_Speed.pdf?ext=.pdf
8. Haddon W Jr. Energy damage and the ten countermeasure strategies. J trauma. 1973;13(4):321–31. Doi:1097/00005373-197304000- 00011.https://pubmed.ncbi.nlm.nih.gov/4700110/ 
9. Khorasani-Zavareh, D., Bigdeli, M., Saadat, S., & Mohammadi, R. Kinetic energy management in road traffic injury prevention: a call for action. Journal of injury & violence research. 2015; 7(1): 36-37. 
   https://pmc.ncbi.nlm.nih.gov/articles/PMC4288294/
10. National Library of Medicine. August 28, 2023. Accessed February 25, 2025. https://www.ncbi.nlm.nih.gov/books/NBK441955/#:~:text=Frontal%20and%20near%2Dside%20collis
    ions,Scene%20Assessment%20of%20Damage
11. Young, L., Rule G., Bocchieri, R., Waliko, T., Burns, J., & Ling, G. When physics meets biology: low and high velocity penetration, blunt impact, and blast injuries to the brain. Frontiers in Neurology. 2015; 6. https://doi.org/10.3389/fneur.2015.00089 
12. Figure 3. Foundation for Traffic Safety. Risk of Pedestrian Death in Relation to Impact Speed. Adapted from University of Berkeley Safe Transportation Research and Education Center. https://safetrec.berkeley.edu/tools/california-safe-speeds-toolkit/california-safe-speeds-toolkit-research-speeds-speed-limits-and

Supplemental Source

1. Doecke, S., Baldock, M., Kloden, C., & Dutschke, J. (2020). Impact speed and the risk of serious injury in vehicle crashes. Accident Analysis & Prevention, 144. https://www.sciencedirect.com/science/article/pii/S0001457519318408 
2. Figure 3 data source:  https://www.sciencedirect.com/science/article/pii/S000145751200276X?via%3Dihub

NV Law Enforcement Non-Adjudicated Traffic Citation Data was obtained from the Nevada Office of Traffic Safety. This research was made possible by a grant from the Nevada Office of Traffic Safety #TS-2025-UNLV-09