Speeding and Speed Management
NHTSA defines a crash to be speeding-related if any driver involved in the crash is charged with a speeding-related offense or if a police officer indicates that racing, driving too fast for conditions, or exceeding the posted speed limit was a contributing factor in the crash. Speeding-related fatalities have generally decreased over the last decade, as shown in the figure below. However, speeding and racing increased during the early months of the pandemic in 2020. In 2021 there were 12,330 speeding-related fatalities, an increase of 8% from the 11,428 fatalities in 2020 (Stewart, 2023). Speeding was a contributing factor for 29% of fatalities in motor vehicle traffic crashes in the United States in 2021, the highest percentage since 2013 (NCSA, 2022; Stewart, 2023).
Speeding-Related Fatalities by Year and as a Proportion of Total Fatalities
Sources: NCSA (2022); Stewart (2023)
Speeding is legally defined by States and municipalities in terms of a “basic speed rule” and statutory maximum speed limits. The basic speed rule generally requires drivers to operate a vehicle at a speed that is reasonable and prudent for roadway conditions. Deciding to take enforcement action is at the law enforcement officer’s discretion, which may be affected by weather, surface conditions, traffic volume, and special locations (e.g., work zones, school zones, or other environmental conditions). Statutory speed limits set maximum limits for different types of roads, and generally apply to all roads of that type even when the limits are not posted. Generally applicable limits can be superseded by specific limits posted for roadway segments, usually determined by an engineering study.
Speeding can be dangerous on all types of roads, but particularly on non-interstate rural and urban roadways. In 2020 some 38% of speeding-related fatalities occurred on non-interstate rural roadways, another 49% on non-interstate urban roadways, 8% on interstate urban roadways, and 5% on interstate rural roadways (NCSA, 2022). These percentages do not, however, account for the extent of miles of each road type or VMT on these different road types.
Drivers widely admit to speeding in national surveys. Forty-three percent of drivers in a nationally representative online survey reported driving more than 15 mph over the limit on a freeway in the past month (AAAFTS, 2016). Almost the same percentage admitted to speeding more than 10 mph over the limit on a residential street within the past month.
Speeding becomes an element of aggressive driving when a vehicle’s speed substantially exceeds the prevailing travel speeds of other vehicles, and other driving behaviors contribute to unsafe conditions, such as tailgating, weaving, and rapid lane changes. Speeding is a more clearly defined problem than aggressive driving, and strategies to reduce speeding (and other serious traffic law violations) may provide a means to address the problem of aggressive driving. However, speeding is among the most complex traffic safety issues to address and requires a multi-disciplinary approach.
Aggressive and risky driving actions are also perceived to be common, although they are difficult to measure accurately. The 2014 survey by AAAFTS suggests that angry and aggressive driving are increasing, with more than 78% of drivers reporting they engaged in at least one instance of aggressive driving over the previous year including tailgating other drivers to get them to speed up or move over (51%), blocking other vehicles from changing lanes (24%) or cutting off another vehicle on purpose (12%) (AAAFTS, 2016). Nearly 4% of drivers even admitted to engaging in actions that would be considered road rage incidents.