1.1 Cell phone laws
Cell phones have become an essential feature of modern life. In June 2004, about 170 million Americans had a cell phone, an increase of more than 20 million from 2003 (CITA, 2004). About two out of every three drivers now have a cell phone, and before long almost all of them will. In NHTSA's 2002 national telephone survey, 60 percent of drivers reported that they had a cell phone and about one-third of all drivers used a cell phone at some time while driving (Royal, 2003, p. 20). NHTSA's 2002 national observation survey found that 4 percent of drivers on the road at any time were using handheld cell phones (Glassbrenner, 2003). Several statewide surveys found similar use rates (McCartt and Hellinga, 2005).
While more than 100 research studies have investigated various aspects of cell phone use, they do not provide clear answers to critical questions (McCartt and Hellinga, 2005). Experiments on simulators or test tracks document that cell phone use has some effect on driving performance but these experiments cannot measure the impact on crash risk. Most studies find similar effects for handheld and hands-free phones. Most crash studies rely on driver's own reports or on law enforcement investigations to estimate whether cell phone use contributed to the crash. A recent review of these studies concluded that cell phones are involved in 1 to 4 percent of crashes (an amount consistent with the 2 percent found in NHTSA's telephone survey and crash investigations discussed in the Overview) and that cell phone use increases crash risk by a modest amount (McCartt and Hellinga, 2005).
While cell phone use occurs less frequently than other driver distractions (see Overview), it has been singled out for special attention, probably for several reasons. Cell phone use is a multi-sensory distraction, requiring a driver's eyes to locate a ringing phone, hands to hold or dial the phone, hearing to listen to the call, and attention to carry on a conversation. Handheld cell phone use is easy to observe and may send the message that drivers using cell phones are more interested in their conversations than they are in driving safely. Several highly publicized crashes have been attributed to cell phones.
In response to these concerns, the District of Columbia , New Jersey , New York , and several communities prohibit handheld cell phone use while driving (GHSA, 2005; NCHRP, under review, Strategy C2; Sundeen, 2003). Several States prohibit all cell phone use by drivers under the age of 18 or 21, drivers with a GDL, and school bus drivers. Other States do not allow communities to restrict cell phone use. Legislatures in over two-thirds of the States have considered bills related to cell phone use in each recent year: 37 in 2005 (Copeland, 2005) and 42 in 2003 (Sundeen, 2003). No United States jurisdiction restricts hands-free phone use for all drivers. Many European countries and all Australian States prohibit handheld phone use (McCartt and Hellinga, 2005).
Use: T he District of Columbia, New Jersey, New York, and about two dozen communities prohibit handheld cell phone use while driving (GHSA, 2005; Sundeen, 2003).
Effectiveness: The only evaluation data in the United States comes from two studies of New York 's 2001 law. Observation studies found that handheld phone use by drivers on the road dropped from 2.3 percent pre-law to 1.1 percent a few months after the law and then returned to pre-law levels during the subsequent year. The authors note that publicity regarding the law diminished substantially after the law was implemented and no targeted enforcement was conducted (McCartt and Geary, 2004). A telephone survey found that the proportion of drivers who reported using a cell phone at least once increased from 38 percent immediately before the law to 45 percent about 18 months after the law. Hands-free use increased only slightly (McCartt and Hellinga, 2005).
Costs: As with any law, costs are required to publicize and enforce it. New York 's experience suggests that a strong communications campaign and vigorous enforcement may be necessary to reduce cell phone use over the long term. A handheld cell phone law can be enforced during regular traffic patrol because cell phone use can be observed easily, so that enforcement costs should be minimal. Publicity can be expensive. Paid advertising supporting highly visible law enforcement may be necessary to achieve substantial effects. Paid advertising can be expensive: for example, costs for some belt use enforcement campaigns in 2003 averaged $500,000 per State (Chapter 2, Section 2.1; Solomon et al., 2003).
Time to implement: A cell phone law can be implemented quickly, as soon as it is publicized.