Background Info

Speeding is associated with motor vehicle crashes and related injuries in the United States (U.S.) [1]. In 2021, speeding was associated with 12,330 deaths in the U.S. [2]. In addition to speeding, environmental factors such as traffic flow, road and weather conditions, time of day, etc., have also shown to play a role in motor vehicle crashes and related injuries [3, 4, 5, 6]. A study by Lankarani et al., (2014) suggests that lighting at the scene of crash (night, sunset, sunrise), weather conditions (cloudy, dusty, fog, snow, rain), roadway geometrics (straight and uphill/downhill road, winding road and flat, winding road and uphill/downhill) and road surface (wet, freezing and snow, sandy) are related to traffic crashes, injuries and deaths [7]. In the U.S. in 2021, fatal car crashes occurred more frequently on weekends, with an increase on Saturday when compared to non-fatal crashes which were higher on weekdays and peaked on Friday [8]. Moreover, between 2007-2016, an average of 5,000 deaths occurred due to inclement weather related car crashes in the U.S. [3].

Speeding is also associated with motor vehicle crashes and injuries on Nevada roadways. For example, in Nevada, speeding contributed to the deaths of 496 road users from 2016-2020 [8]. In addition, this report indicates that the greatest number of fatal speeding related crashes in Nevada during 2016-2020 occurred between the hours of 3:00 PM – 11:59 PM and that 67% of speeding related crashed occurred from Thursday to Sunday [9].

Previously, our TREND 12.3 Newsletter focused on a statewide descriptive analysis of speeding related non-adjudicated citations that were associated with a crash versus non-crash from 2018 to 2021. This TREND in Focus reports the descriptive analysis of the environmental factors associated with crash vs. non-crash speeding related non-adjudicated citations in Nevada from 2018-2021 based on data received from the Nevada Office of Traffic Safety (NVOTS).

Nevada Speeding Related Citations that Resulted in a Crash vs Non-Crash Summary

The unit of analysis was citation(s) issued by Nevada law enforcement officers. The results of the analysis are indicated below:

• In Nevada, between the years 2018-2021, a total of 1,425,762 citations were issued by law enforcement agencies. Of those citations, 759,338 (53.3%) were related to speeding.
• The breakdown of 759,338 speeding related citations are as follows:
  • 17,579 (2.3%) citations were associated with a crash (C)
  • 741,759 (97.7%) citations were not associated a crash (NC)
• Approximately three-fourths (75%) of both crash and non-crash speeding related violations occurred between 8:00am – 8:00pm [Figure 1].
• Non-crash speeding related violations were most frequently issued on a Wednesday (18.2%), while crash speeding related violations were issued in approximately equal proportions throughout the weekday [Figure 2].
• January, March, May, and July had the highest frequencies of non-crash speeding related citations issued (~ 9% each), while crash speeding related citations were issued in approximately equal proportions throughout the year (~ 0.20 ± 3%) [Figure 3].
• Over half (51.2%) of non-crash speeding related violations occurred when there was light traffic on the road, while most crash speeding related citations (0.97%) occurred when there was medium traffic on the road [Figure 4].

*Note: findings should be interpreted with caution given the significant sample size differences between non-crash vs. crash citations.

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-2023-UNLV-00077.

TREND in Focus References:

1. National Safety Council. Motor Vehicle Safety Issues. Accessed August 11, 2023. http://injuryfacts.nsc.org/motor-vehicle/motor-vehicle-safety-issues/speeding/
2. National Highway Traffic Safety Association. Speeding Catches Up With You. Accessed August 11, 2023. https://www.nhtsa.gov/risky-driving/speeding
3. U.S. Department of Transportation Federal Highway Administration. How Do Weather Events Impact Roads? Accessed August 11, 2023. https://ops.fhwa.dot.gov/weather/q1_roadimpact.htm
4. Osman, M., Paleti, R., & Mishra, S. Analysis of passenger-car crash injury severity in different work zone configurations. Accident Analysis & Prevention, 111, 161-172; 2018.
5. Qiu, L., & Nixon, W.A. Effects of adverse weather on traffic crashes: systematic review and meta-analysis. Transportation Research Record, 2055(1), 139-146; 2008.
6. Retallack, A. E., & Ostendorf, B. Relationship between traffic volume and accident frequency at intersections. International Journal of Environmental Research and Public Health, 17(4), 1393; 2020
7. Lankarani, K. B., Heydari, S. T., Aghabeigi, M. R., Moafian, G., Hoseinzadeh, A., & Vossoughi, M. (2014). The impact of environmental factors on traffic accidents in Iran. Journal of Injury and Violence Research, 6(2), 64–71. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4009171/
8. National Safety Council. Crashes by Time of Day and Day of Week. Accessed August 11, 2023. https://injuryfacts.nsc.org/motor-vehicle/overview/crashes-by-time-of-day-and-day-of-week/
9. Zero Fatalities. Nevada Fatal Crash Data. Accessed August 17, 2023. https://zerofatalitiesnv.com/app/uploads/2023/01/Nevada-Crash-Facts-2022-2023.pdf

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