In the HVE model, law enforcement targets selected high-crash or high-violation locations, corridors, or geographical areas for enhanced enforcement, and publicizes the enforcement widely to maximize general deterrence of speeding beyond those who are stopped. If done well, such a campaign should be perceived as fair, as drivers are being put on notice that the enforcement is occurring, and that it is being done to improve safety. This model is based on the same principles as high-visibility seat belt and alcohol-impaired-driving enforcement. The objective is to convince the driving public that speeding is likely to be detected and therefore not worth the risk of receiving fines, points, or other punishment. (See the chapters on Alcohol-Impaired Driving and Seat Belt Use for more information.)
Enforcement actions for speeding violations should be fair, consistent with local and State statutes, and taken in the interest of preventing traffic crashes. Correspondingly, locations with a demonstrable speeding and heightened crash risk are most recommended for focused enforcement activities.
Effective communications and outreach have long been deemed an essential part of successful speed and aggressive-driving enforcement programs (Neuman, Pfefer, Slack, Hardy, Raub, et al., 2003; Neuman et al., 2009) as well as Speed Safety Camera programs (NHTSA & FHWA, 2023). Key objectives of these communications are to provide information about the program and expected safety benefits, to incorporate public input (which requires two-way communications), and to increase community support.
Beyond these general communications to help create a fair and effective enforcement program, a key objective of publicity is to maximize the general deterrent effects of enforcement by increasing the perception among drivers (not all of whom can be ticketed) that they will be caught speeding. Other State and community partners may help to leverage resources and achieve a wider reach if they have common goals and concerns (GHSA, 2018b).
Most States provide some funding for speed equipment (47 States and Guam), overtime enforcement (42 States and Guam), or speed public information campaigns (31 States and Guam) (Sprattler, 2012). A 2021 GHSA review of HVE practices and strategies with select State highway safety office officials and law enforcement agencies suggests that HVE is decreasing, along with grant-funded support for such activities (Byrne et al., 2021).
A survey of State practices for GHSA in 2012 found that relatively few States funded aggressive driving enforcement at that time (Sprattler, 2012), and it is likely that high-visibility aggressive driving enforcement campaigns are not common. The 2012 GHSA report (Sprattler, 2012) and a guide from the NCHRP program (Neuman, Pfefer, Slack, Hardy, Raub, et al., 2003) provide a few examples of aggressive driving enforcement programs.
Overall, HVE deters speeding where and while being used (if intense enough and implemented well), but some research indicates that effects may disappear within weeks or months once the programs end (Vision Zero SF, 2020). Evaluations of high-visibility speed enforcement programs suggest that intense campaigns with publicity can deter speeding on target urban corridors. San Francisco, California, implemented a year-long HVE program focusing on 11 high injury corridors as a component of Vision Zero efforts during 2016-2017 (Vision Zero SF, 2020). During the most active part of the enforcement campaign, the enforcement was supported with variable message signs deployed on the Sunday evening prior to scheduled enforcement on a given corridor. In addition, varied types of media, online marketing, physical communications (i.e., rear of bus and bus shelter ads), and community-based local activities were performed. More than 1,800 speeding citations were issued to drivers on the target corridors with 1,400 more issued citywide. A controlled evaluation found that 85th percentile and mean speeds were reduced by about 5% during the enforcement actions. The time periods just prior to enforcement periods when the variable message signs were present, but enforcement had not yet begun, also showed a modest reduction in speeds indicating a publicity effect of the signs deployed at the corridor level. However, there was no lasting effect of the enforcement. Speeds started climbing within one week following the last enforcement on a corridor, and by the following month there was no detectable effect on speeding (Vision Zero SF, 2020).
A substantial increase in general traffic enforcement in Fresno, California, that included an increase from 20 to 84 traffic patrol officers, the addition of 20 new police motorcycles and radar guns, and more than three-fold increase in citations in 2 years was associated with decreases in motor vehicle crashes, injury and fatal crashes, and lower rates per population compared to the county where enforcement decreased slightly (Davis et al., 2006). A 2008 test of a 4-week, HVE campaign along a 6-mile corridor with a significant crash history in London, U.K., found significant reductions in driver speeding in the enforced area. There was also a continuing effect up to 2 weeks following the end of the campaign (Walter et al., 2011). A crash-based analysis was not conducted. The campaign was covered by print media as well as by billboards and active messaging along the enforced corridor.
Several earlier NHTSA-supported demonstration programs saw more mixed success. All three demonstrations lasted 6 months and included extensive publicity but differed in other respects. Milwaukee was the most successful. Red light running decreased at targeted intersections. Crashes in the city dropped by 12% in targeted corridors and by 2% in comparison corridors (McCartt et al., 2001). The Indianapolis demonstration was not a success. Average speeds dropped slightly. Total crashes increased 32% over the previous year (Stuster, 2004). Crashes increased more in the demonstration area than in other areas, and the proportion of crashes involving aggressive driving behaviors also increased in the demonstration areas. Stuster indicated that the most likely explanation for the increases was inaccurate traffic volume data extrapolated from previous years and neighboring areas. Tucson had mixed results. Average speeds dropped moderately (Stuster, 2004). Total crashes increased 10% in the demonstration areas and decreased in comparison areas. However, the proportion of crashes involving aggressive driving behaviors decreased by 8% in the demonstration areas.
There is less evidence about such campaigns on rural roads, and evidence is mixed from “rational speed limit setting and enforcement’ demonstration programs on rural highways, likely due to difficulty in achieving sustained, higher enforcement levels and other variations in programs and evaluations (e.g., Freedman et al., 2007).
There is evidence that publicity enhances safety effects of an enforcement campaign, although there has been more success with seat belts and impaired driving campaigns. A meta-analysis of 67 worldwide studies of the effect of road safety campaigns on crashes suggests a general campaign effect of 9% crash reductions; however, anti-drunk-driving campaigns were considerably more effective than anti-speeding campaigns (Phillips et al., 2011). Roadside message delivery, use of enforcement, personal communication or a combination of personal communication with mass media, were other factors associated with greater crash reductions, whereas more recent campaigns (after 2000) tended to be less effective than those before 2000.
Other evidence comes from publicity associated with automated enforcement programs. Reductions in crashes in Victoria, Australia, were attributed to a television advertising campaign that supported, but did not relate directly, to automated speed enforcement initiatives (Bobevski et al., 2007). As mentioned in the SSC Countermeasure section, a study from Charlotte also found that publicity from an aggressive media outreach campaign and on-going publicity related to automated enforcement was responsible for an 8% to 9% reduction in crashes. Effects carried over for several months after the program ended before gradually returning to pre-intervention levels (Moon & Hummer, 2010). Earlier evidence from Australia also suggested that paid media advertising could enhance the effectiveness of automated speed enforcement (Cameron et al., 1992).
As mentioned above, signs rolled out in advance of enforcement actions in San Francisco’s high-visibility speed enforcement campaign were associated with a 3% reduction in 85th percentile speeds. This is consistent with the Phillips et al. (2011) finding that direct communications at the roadside are likely more effective than general mass media publicity. As found in Philadelphia’s Heed the Speed campaign, achieving message penetration through signs, flyers, and other community outreach approaches is a challenge in a large urban setting (Blomberg et al., 2012).
Communications and outreach programs urging drivers to behave courteously or to not speed are unlikely to have any effect unless they are tied to vigorous enforcement (Neuman, Pfefer, Slack, Hardy, Raub, et al., 2003). Campaign messages that are pre-tested to ensure they are relevant to the target audience and that reach the audience with sufficient intensity and duration to be perceived and noticed are most likely to be effective (Preusser et al., 2008).
High-visibility model programs to target specific aggressive driving actions around large trucks have also been undertaken in several States, but there is as yet, no crash-based evidence available. The program, known as TACT (Ticketing Aggressive Cars and Trucks) is modeled on the Click It or Ticket belt use campaigns. An evaluation found promising results in reducing the number of targeted violations as the program was implemented in Washington State; effects on crashes or injuries were not determined (Nerup et al., 2006; Thomas, Blomberg, et al., 2008). The TACT program was also used in Michigan. The evaluation of this program by Kostyniuk et al. (2014) indicates that TACT messages reminding drivers of the slogan “Leave More Space for Trucks” were successfully received, with 40% of drivers being aware of the slogan. However, given the awareness of this slogan, behaviors of both light vehicle drivers did not change when driving around trucks. A unique part of this implementation of the TACT program was the visibility of two of four police vehicles at one time in a relatively small geographical location. From a deterrence perspective, because drivers generally revert back to the “old behaviors” once a police car passes by, having a second police car available to follow up once drivers think they can revert back to unsafe behavior increases the likelihood that these violators will be apprehended.
In summary, the evaluation evidence suggests that high-visibility, anti-speeding enforcement and publicity campaigns have promise, but safety benefits are far from guaranteed, and are difficult to sustain without continued investment.
As with alcohol-impaired driving and seat belt use enforcement campaigns, the main costs are for law enforcement time and for publicity. A Minnesota Speed Management Program cost approximately $3 million, with $2.5 million for increased enforcement, $350 thousand for paid media (primarily radio), and $150 thousand for data collection and evaluation. The Minnesota DOT and State Patrol also made significant in-kind contributions toward project management, sign installation, speed detection equipment, engineering reviews, and fuel and vehicle costs (Harder & Bloomfield, 2007). The three NHTSA-sponsored demonstration projects, Aggression Suppression in Milwaukee (McCartt et al., 2001), Rub Out Aggressive Driving in Indianapolis (Stuster, 2004), and We’ve Got Your Number in Tuscon (Stuster, 2004), overviewed in the effectiveness section had different funding costs. The Milwaukee demonstration received a $650,000 grant (McCartt et al., 2001) and the other two demonstrations in Indianapolis and Tuscon each received a $200,000 grant (Stuster, 2004). Public-private partners (such as those in interests in injury prevention and public health) may be able to assist with publicity. The cost of the previously mentioned Fresno demonstration included a $70,000 grant from the California State Office of Traffic Safety (Davis et al., 2006). A citation revenue sharing agreement between the city and county was developed in which speeders paid the enforcement costs, rather than taxpayers.
Time to implement:
High-visibility enforcement campaigns may require 4 to 6 months to plan, publicize, and implement.
- Work Zone speed enforcement: Researchers found that stationary police vehicles were effective in Indiana work zones, whereas enforcement patrol was ineffective at lowering speeds in work zones (Chen & Tarko, 2012). In addition, using variable message signs upstream of the stationary vehicle, near the beginning of the work zone was also effective. While effectiveness varied by work zone, the general effective length or distance for a stationary police vehicle was about one mile, suggesting that longer work zones may require several police vehicles deployed at intervals of about one mile.
- Sustained effort is necessary: Time (and distance) effectiveness is limited, although program publicity may help to generate somewhat longer-lasting effects. Speed enforcement must be continued at frequent intervals as drivers will quickly revert to speeding. Methods making use of enforcement halos such as enforcing a corridor or other area intensely, and then rotating the enforcement to another zone could also be used to maximize enforcement’s deterrent effects. As mentioned in the section on Speed Safety Camera Enforcement, researchers determined that the time halo effects were strongly related to the number of site visits per week and the enforcement hours per week (Gouda & El-Basyouny, 2017b). They used the analysis to estimate an optimal deployment scenario for the jurisdiction (estimated at eight visits a week for 22 hours, approximately 2.7 hours per visit), which they estimated would result in a 5-day effectiveness halo of reduced speeding. Another approach to generate wider deterrence in Queensland was to randomly target moderate to low levels of conspicuous enforcement on an unpredictable basis to a larger share of network roads that account for a significant majority of injury crashes on the entire network (Newstead et al., 2001). Significant reductions of 12% in all severity crashes and 15% in fatal crashes were estimated. Enhancing such an enforcement strategy with more publicity and signs could potentially increase the safety effects.