2. Safety Belt Use

Overview

Wearing a safety belt is the single most effective way to save lives and reduce injuries in crashes. NHTSA (2001, pp. 9, 13) estimates that safety belts in passenger cars (a manual lap- and shoulder-belt combination) reduce serious injuries by 69 percent and fatalities by 45 percent. In comparison, air bags without safety belts reduce serious injuries by 30 percent and fatalities by 14 percent. Safety belts are similarly effective for pickup truck and other light-truck occupants.

The challenge is to convince all passenger vehicle occupants to buckle up. Current data shows that, for adult drivers and passengers:

• safety belt use nationwide reached 82 percent in June 2004 (Glassbrenner, 2004b);
  
  
• in 2004, belt use was greater than 90 percent in six States ( Arizona , California , Hawaii , Michigan , Oregon , and Washington); but
  
  
• in 2004, belt use was less than 65 percent in four States ( Arkansas , Massachusetts , Mississippi , and New Hampshire [in 2003]) (Glassbrenner, 2004c).

See NHTSA's most recent reports (Glassbrenner 2004b, 2004c) for the latest national and State data.

This chapter addresses only safety belt use by adults and older children. Younger children require infant, child safety, or booster seats appropriate to their size and weight and are covered by separate restraint use laws. Many issues and strategies for increasing child occupant protection are quite different from those raised by adult belt use.

Source: NHTSA, Office of Impaired Driving and Occupant Protection

Trends. All new passenger cars had some form of safety belts beginning in 1964, shoulder belts in 1968, and integrated lap and shoulder belts in 1974 (ACTS, 2001, Appendix A). Few occupants wore the belts: surveys in various locations recorded belt use of about 10 percent. The first widespread survey, taken in 19 cities in 1982, observed 11 percent belt use for drivers and front-seat passengers (Williams and Wells, 2004). This survey became the benchmark for tracking belt use nationwide. The chart above shows the best available estimate of national belt use annually since1982.

New York enacted the first belt use law in 1984. Other States soon followed. In a typical State, belt use rose quickly to about 50 percent shortly after the State's belt law went into effect. Over the next year the rate usually decreased slightly, on average by about four percentage points (Nichols, 2002).

High-visibility short-duration belt law enforcement programs, often called STEPs (Selective Traffic Enforcement Programs), "STEP waves," or "blitzes," were demonstrated in individual communities in the late 1980s. North Carolina 's "Click It or Ticket" program took this model statewide beginning in 1993 and raised the use rate above 80 percent (Williams and Wells, 2004). Statewide, multi-State, and national enforcement programs increased through the 1990s under different names and sponsors. These enforcement programs typically raised belt use by 13 to 26 percentage points, with greater gains where belt use was lower (Dinh-Zarr et al., 2001; Nichols, 2002). Belt use often decreased by about 6 percentage points after the enforcement program ended.

Recently, the Click It or Ticket model has expanded beyond North Carolina : To South Carolina in 2000, to all eight States of NHTSA's Southeast Region in 2001, and nationally in 2003 (Solomon et al., 2004). Recent programs have extensively used paid advertising as part of their communications and outreach strategies. They raising the national belt use rate to 82 percent in 2004 (Glassbrenner, 2004b).

For more information on the history of belt systems, belt use laws, enforcement programs, and belt use trends, see ACTS (2001), Solomon et al. (2004), Milano et al. (2004), NCHRP (2004), NHTSA (2001, 2003), and Williams and Wells (2004).

Belt use laws. As of July 2005, all States except New Hampshire required adult passenger vehicle occupants to wear belts. The laws in 22 States and the District of Columbia permit law enforcement to stop and cite all nonusers. These are called primary enforcement laws. The remaining 27 States have secondary enforcement laws that allow nonusers to be cited only after they first have been stopped for some other traffic violation (Glassbrenner, 2004c). Fines in primary law States range from $10 to $200 with a fine of $25 or more in all but four States. Fines in secondary law States range from $10 to $75 with a fine of $25 or less in all but two States (Glassbrenner, 2004c). Some laws cover only front-seat occupants or allow other exemptions.

Strategies to Increase Belt Use

The basic strategy for achieving and maintaining high belt use is highly publicized high-visibility enforcement of strong belt use laws. This strategy's effectiveness has been documented repeatedly in the United States and abroad. The strategy's three components -- laws, enforcement, and publicity -- cannot be separated: effectiveness decreases if any one is weak or lacking. The sections in this chapter discuss each component's key features. Some communications and outreach and incentive programs directed to well-defined and limited audiences such as schools, businesses, and communities have been moderately successful and also are discussed in this Chapter. NCHRP (2004) discusses several of these strategies and provides links to additional information.

Safety belt use also may be affected by vehicle design features such as the comfort and convenience of belt systems, and by lights or buzzers to remind occupants to buckle up (NHTSA, 2003). These vehicular countermeasures are not included in this guide because SHSOs have little or no authority or responsibility for them.

Key terms Primary enforcement: laws that permit nonusers to be stopped and cited by a law enforcement officer independently of any other traffic behavior. Secondary enforcement: laws that permit nonusers to be cited only after they have been stopped for some other traffic violation.

Countermeasures That Work

Countermeasures to increase safety belt use are listed below and discussed individually in this chapter. The table is intended to give a rough estimate of each countermeasure's effectiveness, use, cost, and time required for implementation. The terms used are described below. Effectiveness, cost, and time to implement can vary substantially from State to State and community to community. Costs for many countermeasures are difficult to measure, so the summary terms are very approximate. See each countermeasure discussion for more information on each item.

1. Safety belt use laws

Countermeasure	Effectiveness	Use	Cost	Time
1.1 State primary enforcement belt use laws	Proven	Medium	Low	Short
1.2 Local primary enforcement belt use laws	Likely	Low	Low	Short
1.3 Increased belt use law penalties	Likely	Low	Low	Short
1.4 Coverage: seating position, vehicles, ages	Unknown	Medium	Low	Short

2. Safety belt law enforcement

Countermeasure	Effectiveness	Use	Cost	Time
2.1 Short high-visibility belt law enforcement	Proven	Medium*	High	Medium
2.2 Sustained enforcement	Uncertain	Unknown	Varies	Varies
2.3 Combined enforcement, nighttime	Likely	Unknown	High	Medium

* Used in many jurisdictions but often only once or twice each year

3. Communications and outreach

Countermeasure	Effectiveness	Use	Cost	Time
3.1 Supporting enforcement	Proven	Medium	Varies	Medium
3.2 Strategies for low-belt-use groups	Uncertain*	Unknown	Unknown	Medium

* For stand-alone programs not supporting enforcement

4. Other strategies

Countermeasure	Effectiveness	Use	Cost	Time
4.1 Employer and school programs	Proven*	Unknown	Varies	Varies
4.2 Incentive programs	Proven*	Low	Varies	Medium

* In low-belt-use settings with no belt use law

Effectiveness:

Proven: demonstrated by several high-quality evaluations with consistent results.
Likely: balance of evidence from high-quality evaluations or other sources.
Uncertain: limited and perhaps ambiguous evidence.
Unknown: no high-quality evaluation evidence.
Varies: different methods of implementing this countermeasure produce different results.

Effectiveness is measured by increases in observed safety belt use. See individual countermeasure descriptions for information on effectiveness size and how effectiveness is measured.

Use:

High: more than two-thirds of the States, or a substantial majority of communities.
Medium: between one-third and two-thirds of States or communities.
Low: fewer than one-third of the States or communities.
Unknown: data not available.

Cost to implement:

High: requires extensive new facilities, staff, equipment, or publicity, or makes heavy demands on current resources.
Medium: requires some additional staff time, equipment, and/or facilities.
Low: can be implemented with current staff, perhaps with training; limited costs for equipment or facilities.

These estimates do not include the costs of enacting legislation or establishing policies.

Time to implement:

Long: more than one year.
Medium: more than three months but less than one year.
Short: three months or less.

These estimates do not include the time required to enact legislation or establish policies.