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Effectiveness: 2 Star Cost: $
Use: Medium
Time: Short

Overall Effectiveness Concerns: The effectiveness of laws banning cell phone use has been examined in several research studies. The results across types of phone use are inconsistent. Specifically, research examining prohibitions on hands-free phone use and texting have yielded mixed results in terms of reductions in phone use while driving and reduced crashes. There is some evidence that banning handheld cell phone use leads to long-term reductions in this behavior; however, many State and Local laws were only recently passed and effectiveness is still being examined. At this time, there is insufficient consensus across research findings to determine that this countermeasure is effective.

Cell phones have become an essential feature of modern life. In a 2015 NHTSA survey of more than 6,000 U.S. residents, 42% admitted to answering phone calls while driving and 56% of these drivers continued driving while talking on the phone (Schroeder et al., 2018). NHTSA’s 2018 national observation survey found 3.2% of drivers on the road at any given moment were using handheld cell phones (NCSA, 2019). The percentage of drivers who were manipulating a handheld device (e.g., texting or dialing) increased from 0.6% in 2009 to 2.1% in 2018. NHTSA currently estimates that 9.7% of drivers are using some type of phone (handheld or hands-free) in a typical daylight moment. These estimates may underrepresent cell phone use given the inherent difficulty in accurately observing these behaviors.

Many studies have investigated the effects of cell phone use on driving (see Caird et al., 2008, and McCartt et al., 2006, for reviews). Experiments on simulators or test tracks indicate that talking on cell phones has some effect on driving performance, most commonly slowed reaction times, but these experiments cannot measure the impact on crash risk. For reasons outlined in the overview, it can be difficult to determine whether cell phones contribute to individual crashes. Two studies examining cell phone billing records concluded that drivers are four times more likely to be involved in a serious crash when talking on cell phones (McEvoy et al., 2005; Redelmeier & Tibshirani, 1997). In addition, these two studies and others have found that hands-free phones offer little or no safety advantage over handheld phones (Caird et al., 2008; Ishigami & Klein, 2009). However, more recent studies have questioned the estimates of crash risk and argued the real risk may be much smaller (Farmer et al., 2010; Young, 2012). Analyses of crash events using SHRP2 NDS data found that aspects of cell phone use are associated with increased odds of crash events (Dingus et al., 2016). The table below shows the increase in odds and the baseline prevalence of the distraction in terms of the percentage of time drivers engaged in a distracting task while driving. Actions such as dialing and texting show substantially elevated odds of crash events, especially in comparison to more traditional sources of distraction, such as tuning a radio (odds ratio of 2.9) and talking to a passenger (odds ratio of 1.4), which are not shown in the table.

 

Type of Cell Phone Distraction

Change in Risk (Odds Ratio)

Baseline Prevalence

Total cell (handheld)

3.6

6.4%

 Cell dial (handheld)

12.2

0.1%

 Cell text (handheld)

6.1

1.9%

 Cell reach

4.8

0.6%

 Cell browse

2.7

0.7%

 Cell talk

2.2

3.2%

 Note: All odds ratios statistically different from 1 at the 0.05 level of significance. 
Source: Dingus et al. (2016).

There is less disagreement about the dangers posed by texting while driving. In a study using highly instrumented commercial motor vehicles, texting drivers were 23 times more likely to be involved in a crash, near-crash, or other safety-critical event compared to uneventful baseline driving (Olson et al., 2009). This is supported by experimental studies using driving simulations, which suggest that texting drivers spend up to 400% more time looking away from the road and are more likely to leave their lane than when not text messaging (Drews et al., 2009; Hosking et al., 2009). In the 2015 NHTSA survey, 20% of drivers admitted to sending text messages or emails while driving (Schroeder et al., 2018).

States have been very active in using legislation to address this issue. Since 2000 every State has considered legislation to curtail distracted driving or driver cell phone use. In 2015 legislators in 42 States considered approximately 150 bills related to distracted driving (Teigen et al., 2016). No State completely bans all types of cell phone use for all drivers. Bans on texting are more common than bans on handheld cell phone use. Overall, public support is high for this legislation. In surveys of the general public, between 70% and 80% favor bans on handheld cell phone use, and 88% to 97% support bans on texting while driving (AAAFTS, 2013; Guarino, 2013; Schroeder et al., 2018).

Use: As of February 2020 talking on handheld cell phones was prohibited in 21 States (Arizona [warning period through January 1, 2021], California, Connecticut, Delaware, Georgia, Hawaii, Illinois, Maine, Maryland, Massachusetts, Minnesota, Nevada, New Hampshire, New Jersey, New York, Oregon, Rhode Island, Tennessee, Vermont, Washington, and West Virginia) and the District of Columbia (GHSA, 2020). The cell phone bans in these States are primary laws. In addition, several local jurisdictions such as Hampton, Virginia, and Cheyenne, Wyoming, have enacted their own restrictions on cell phones. At present, no State restricts hands-free phone use for all drivers.

Most States prohibit text messaging while driving. As of February 2020 there were 48 States and the District of Columbia that prohibit text messaging for all drivers (GHSA, 2020).

Effectiveness: Evaluations in New York, Connecticut, the District of Columbia, and in other countries consistently show that cell phone laws reduce handheld phone use by about 50% shortly after the laws take effect (McCartt et al., 2006). The long-term effects of these reductions in handheld cell phone use are unclear (McCartt & Geary, 2004; McCartt et al., 2010), and currently, the effects of these laws on use of hands-free devices is unknown.

The effectiveness of handheld cell phone bans in reducing crashes is still unclear. Nikolaev et al. (2010) examined driving injuries and fatalities in 62 counties in New York State both before and after a handheld cell phone ban took effect. Forty-six counties showed significant decreases in injury crashes following the ban, and 10 counties showed less-significant decreases in fatal crashes. Although encouraging, the study did not include a control group to account for other factors that may have decreased crashes. A study by the HLDI investigated State-level automobile insurance collision claims in California, Connecticut, New York, and the District of Columbia. When compared to neighboring States, there was no change in collision claim frequency after these jurisdictions implemented handheld cell phone bans. The data from the HLDI are proprietary, and not all crashes result in a collision claim, so collision claim rates may differ from crash rates.

Four studies have examined the effectiveness of laws prohibiting cell phone use and texting while driving. One study evaluated the effect of a texting ban in Michigan (Ehsani et al., 2014); another examined insurance collision claims in States with texting bans compared to neighboring States without such bans (HLDI, 2010). Both studies found small increases in  types of crashes and collision claims following enactment of texting bans. One possible explanation is that texting drivers attempt to avoid detection by hiding their phones from view, which may result in more time with drivers’ eyes off the roadway. Crash increases were also found in a study of crash data in New Jersey (Maher & Ott, 2013). While crashes have declined statewide, cell phone-related crashes increased after a cell phone and texting law was enacted. Additionally, the number of citations issued declined after the first year after the ban took effect, possibly because law enforcement resources are limited and issuing citations for cell phone use may be lower in priority compared with other law enforcement objectives. Finally, a review and synthesis of 11 peer-reviewed articles found that, while such bans are highly effective at reducing cell phone use while driving, the effect on crash outcomes is mixed (McCartt et al., 2014). Some studies showed no change in crash rates for both handheld cell phone use and texting, while others showed increases in crashes after the ban (although most of the studies reviewed had limitations that diminish the strength of their conclusions). These findings suggest that the impact on crash rates from cell phone bans is not clear, even though such bans are effective at reducing handheld cell phone use.

Drivers’ attitudes and beliefs about the safety of using cell phones while driving are incongruous with their actions. Maher and Ott (2013) found that New Jersey drivers are knowledgeable about the law and assert that the law is necessary; however, a significant portion also admitted to having violated the law. A more recent national survey indicates that communication of the existence of State laws has generally been effective (Schroeder et al., 2018). Just over 90% of drivers in States that have laws banning cell phones believe that these laws are in place. However, driver perceptions are less accurate in States without these laws, where just over half of drivers incorrectly believe that their State has such a law. The patterns are similar, but slightly lower, when it comes to laws banning texting and emailing, where 78% of drivers correctly report their State does or probably does have a ban. Just over half of drivers in States that do not ban texting and emailing actually believe that such a ban is in place. Driver responses also suggest that communication efforts have fostered the perception that drivers are at risk of getting stopped for cell phone use. Specifically, over half of drivers think that they are very or somewhat likely to get a ticket for talking on cell phones while driving, while only 3.6% of drivers report ever having been stopped for engaging in this behavior (Schroeder et al., 2018).

Costs: As with any law, costs are required to publicize and enforce it. A handheld cell phone law can be enforced during regular traffic patrol because drivers who are using handheld phones can be observed relatively easily. However, some States with cell phone bans allow drivers to use phones for specific purposes while driving (e.g., navigation), which can make enforcement more challenging. As with other traffic safety laws, paid advertising supporting highly visible law enforcement may be necessary to achieve substantial effects (see the Distracted Driving chapter, Section 1.3).

Time to implement: A cell phone law can be implemented quickly, as soon as it is publicized.

Other issues:

    • Cell phone blockers: In recent years, several manufacturers have created systems that can block cell phones from making or receiving calls while people are driving. These systems detect when the phone is in motion. During that time, incoming calls are automatically diverted to voicemail and incoming texts are not shown until the driver has stopped moving. Typically, these systems allow exceptions for phone calls from pre-specified numbers, and some allow emergency calls to 911. Although these systems are potentially applicable to all drivers, they have largely been marketed to parents of teen drivers. Researchers at the Texas Transportation Institute tried to evaluate a cell phone disabling device for teens; however, they encountered difficulty recruiting families and very strong resistance by parents and teens to the device (Benden et al., 2012). NHTSA funded a study examining the effect of a filtering/blocking application on the cell phones of 44 Michigan DOT employees. When the application was active, participants placed and answered fewer calls while their vehicle was in motion. However, participants were not very accepting of the application, and the application was not completely reliable (Funkhouser & Sayer, 2013). NHTSA’s 2015 National Survey on Distracted Driving Attitudes and Behaviors found that 46% of applicants would be open to using an app that would block phone calls and text messaging while driving (Schroeder et al., 2018).
    • Voice-to-text technology: There are several applications that allow drivers to send and receive text messages using voice rather than manual entry. Although the research on these applications is limited, it appears voice-to-text technology may offer little or no safety benefit. In a study by Yager (2013), 42 participants drove instrumented vehicles on a closed course while texting manually or using one of two voice-to-text applications. In all three conditions, reaction times were slower and drivers spent more time looking away from the roadway. More research is needed, but the findings suggest texting impairs driving performance, regardless of what method of texting is used.
    • Enforcement of cell phone and text messaging laws: Enforcement of cell phone use and text messaging laws is challenging. Fewer States ban handheld phone use compared to text messaging. It may be difficult for a LEO to determine whether a driver is messaging or performing other functions on the phone (GHSA, 2013). A NHTSA study conducted in 2013 and 2014 investigated the enforceability of texting laws in Connecticut and Massachusetts (Retting et al., 2017). A range of methods including spotter, stationary, and roving patrols, with variations in the number of patrol officers, uniformed/plainclothes officers, and the conspicuity of patrol vehicles, were used across four enforcement waves. Program evaluation revealed insights for successful enforcement, including officer training, pre-planning of operations, maximizing resources through local and State agency coordination, and the need for strong distracted driving laws. The latter is particularly important in cases where officers may not be able to prove that drivers were texting but can cite the violation of other laws (e.g., handheld cell phone use). Twenty-six police officers from three Washington State counties participated in focus groups to determine factors that influence consistent enforcement of distracted driving legislation (Nevin et al., 2017). The factors that challenged effective enforcement included inconsistency in what corresponds to legal use of handheld devices, policies that do not extend to all drivers under all situations, and lack of clarity in what constitutes a reportable driving violation. Other factors, including officers’ own beliefs and attitudes towards electronics use in their own driving, drivers’ reactions and reasoning of behavior when pulled over, departmental priorities related to distracted driving enforcement, and prevalent local sociocultural norms also affected the success of enforcement practices. Establishment of dedicated traffic patrol units, changes in local public perception through campaigns, and clear delineation between prohibited activities and other electronic device use in the law were improvements that the focus group participants noted might improve the effectiveness of enforcement. In addition, some focus group participants also noted that officer education on distracted driving can bring about a cultural change. The authors developed an educational roll-call video for daily officer briefings that can help curb their own distractions while driving and motivate them to enforce distracted driving (see www.ncbi.nlm.nih.gov/pmc/articles/PMC5927816/bin/NIHMS942376-supplement-Online_Appendix_B.mp4).