Ban Car Alarms Home


Summary of Findings

The Cost of Car Alarms

Audible Car Alarms Don't Work

Auto Theft - Prevention Devices That Do Work

Car Alarms and the Law

Appendix A: Car Alarm Noise Cost Model

Appendix B: Legal Authority of New York City to Ban Audible Car Alarms

Alarmingly Useless: 
The Case for Banning Car Alarms in New York City

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Audible Car Alarms Don't Work


Once a matter of debate, the evidence is now clear: car alarms, for all their sound and fury, do nothing whatever to stop car theft or theft from within cars. "Car alarms are a terrible urban blight with obvious social costs - noise pollution, increased stress, wasted police manpower dealing with broken alarms - and it's not clear there are any benefits in return," says Lawrence Sherman, director of the Jerry Lee Center of Criminology at the University of Pennsylvania. "No study has demonstrated that they reduce auto theft."16

The insurance data are unequivocal. In 1997, the non-profit Highway Loss Data Institute (HLDI) surveyed insurance-claims data from 73 million vehicles, to see which devices could prevent theft. Looking at cars from many different model years, across the country, the study concludes that cars with alarms "show no overall reduction in theft losses" compared to cars without alarms.17 The big auto-makers agree. "An audible system is really just a noisemaker," says General Motors spokesman Andrew Schreck, explaining why only 8% of GM's light duty vehicles have an alarm as standard equipment. "Most people, when they hear an alarm, they just walk the other way."

Experts cite two reasons for the ineffectiveness of audible alarms - the prevalence of false alarms and the professionalization of auto theft.


The vast majority of alarms are false. When staff members at the New York State Legislature researched the issue in 1992, they estimated that 95% of alarms were set off by the vibrations of passing trucks or glitches in the car's electrical system, not by potential thieves.18 That estimate is conservative. Other experts conclude that false alarms account for over 99% of the alarms heard.19 People who live in cities have simply become immune to the alarms' incessant cries for help.

A recent survey by the Ohio-based Progressive Insurance Company found that fewer than 1% of respondents say they would call the police upon hearing a car alarm.20 T.A.'s study found that alarms have prompted fewer than 5% of New Yorkers to ever take action against car theft (fig. 5). Meanwhile, 60% of respondents say they have called the police or taken action against the obnoxious noise created by an alarm (fig. 6). Apparently, the alarms themselves are a much more pressing crime problem than the thieves they are meant to deter.

In New York City, false alarms are so ubiquitous that car owners often don't even pay attention to their own alarms. "If you're in a store, and an alarm goes off in the parking lot outside, do you immediately think it's your car and come rushing out?" asks Brooklyn alarm dealer Norman Maryasis in a candid moment. "No."21 HLDI research confirms these observations. "People tend not to react because the alarms activate so frequently for reasons other than actual theft."22

Alarm manufacturers are well aware of this significant product defect. At a 1992 New York City Council hearing, industry spokesman Darrell Issa admitted that "only in areas where the sound causes the dispatch of the police or attracts the owner's attention is an alarm effective."23 In New York, where neither police nor owners respond to the constant blaring, alarms are uniquely ineffective.


In the past 20 years, car theft has evolved from a juvenile pastime into an $8.2 billion a year business.24 Organized professionals now account for 80% of stolen cars, and alarms don't deter them at all.25 "'Defeating' a car alarm is a non-issue," says criminologist Michael Maxfield, now studying car theft for the state of New Jersey. "Thieves smash windows, yank wires and the alarm is deactivated. Eighty percent of all thieves can and do steal a car with an alarm."

Police officers agree. "Alarms are fine for deterring joy riders," says detective E.S. Hopper, former head of the auto-theft unit in Atlanta. "But it would only be a two-second slowdown for a professional thief."26 Gary Sims, car theft expert for the Los Angeles Police Department, confirms: "I've watched suspects steal a Mercedes that had an alarm system in less than a minute."27

Even alarm installers concede the ease of overcoming an alarm. "The vast majority of alarms can be disabled in, literally, ten seconds," says Micah Sheveloff, a former installer who has reviewed alarm systems for Car Stereo Review magazine. "And a knowledgeable thief can take apart the most sophisticated $1,000 alarm installation in less than 5 minutes."

In her 1992 study, Car Theft: The Offender's Perspective, criminologist Claire Nee presented the only evidence T.A. could find that alarms might actually be an effective deterrent.28 The increasing professionalization of car theft, however, has led her to question her findings. "I suspect the picture has changed dramatically since 1992 when we did the survey," she says. "Car security has improved greatly and there are reasons to believe, if you look at government figures, that 'joyriding' has decreased because of this while 'professional' car theft hasn't."

As alarms become commonplace, even the juvenile joy riders are beginning to defeat them easily. Professor Ronald Clarke, auto theft expert at Rutgers University, notes in his study for the Department of Justice that "interviews with offenders, including joy riders, show a fairly quick learning curve regarding how to deactivate alarm systems."29 In short, car alarms today present no obstacle to the pros, and very little to the amateurs.


Alarms purport to stop theft from cars, not just of cars. No evidence suggests that they are effective here, either. Although theft of car parts in New York plunged over 90% between 1988 and 1998, from 81,970 reported thefts to 7,949,30 police attribute the drop to a crackdown on stolen parts buyers. Between 1995 and 1998, NYPD conducted over 60 sting operations where police offered supposedly stolen parts to dealers.31 The detachable faceplates on car stereos, now available on about 80% of aftermarket systems, have also made a big difference, suggests Professor Andrew Karmen at John Jay College.32

One theory why car alarms do nothing to protect against break-ins is the "moral hazard" or "risk homeostasis" effect: people with alarms are more likely to carelessly leave their valuables in the car, thinking that the alarm will protect them.33

In some anecdotal cases, the overwhelming prevalence of false alarms actually works to thieves' advantage. Journalist Patrick Cooke relates the following story:

"One evening not long ago, while walking his dog along West 77th Street, writer Charles Mann spotted a fellow at the end of the block behaving strangely. 'The guy was going down the street rocking parked cars back and forth,' Mann recalls. This rocking inevitably set a car alarm to wailing. By the time Mann reached the end of the street and saw the broken glass, he had figured out what was going on. 'The thief knew that nobody in the neighborhood would pay the slightest attention to a car alarm,' he says, 'so he used the noise to cover the sound of breaking the window. Then he stole the radio out of the car.'"34

Next: Auto Theft-Prevention Devices That Do Work

16 Quoted in John Tierney, "Laws Encourage Car Alarms, But Din May Not Be Worth It," New York Times, Feb. 19, 1991, pp. A1

17Highway Loss Data Institute, "Insurance industry analyses and the prevention of motor vehicle theft," Business and Crime Prevention (Marcus Felson and Ronald V. Clarke, eds.), pp. 283-93, Monsey, NY: Willow Tree Press, Inc.: 1997

18William Murphy, "It's Simply Alarming: bill would ban noisy anti-theft devices on cars," Newsday, Apr. 28, 1997

19Steven N. Brautigam, "Rethinking the Regulation of Car Horn and Car Alarm Noise: An Incentive Based Proposal to Help Restore Civility to Cities," Columbia Journal of Environmental Law, Vol. 19, pp. 411-12

20supra n.14

21supra n.14

22supra n.17

23Bruce Weber, "Bill to Quiet Wailing Car Alarms Draws Criticism," New York Times, Apr. 21, 1992, pp. B2. Even if the false alarm problem were solved, alarms might remain ineffective, since most people refuse to get involved when they witness street crime. In Fordham University psychologist Harold Takooshian's study, New York's pedestrians, like their counterparts in other cities, ignored a conspicuous thief most of the time. In 8% of the cases, New Yorkers intervened to question a car thief or inform an authority - but 15% of the time, they actually helped the thief break in! See Harold Takooshian and Silva E. Barsumyan, "Bystander Behavior, Street Crime, and the Law," in Studies in Deviance, B.I. Levin, ed., Institute for Sociology, Moscow, 1992

24Federal Bureau of Investigation, Crime in the United States: 2001, Washington DC, pp.53

25See William J. Bratton and William Andrews, "Crime & Punishment: What We've Learned About Policing," City Journal, Vol. 9, No.2, Spring 1999, which claims that organized crime rings are responsible for 70% of the cars stolen in New York City. "Free-lance" professionals steal perhaps another 10%, and amateurs the remaining 20%, according to criminologists' estimates.

26Quoted in Michelle C. Brooks, "Sound the Alarm: An overview of vehicle anti-theft systems," The Atlanta Journal and Constitution, Sept. 23, 1999, pp.6BE

27Quoted in Jeanne Wright, "Your Wheels: The Shocking Truth About the Latest Anti-Theft Gizmo for Cars," The Los Angeles Times, Sept. 10, 1998

28Roy Light, Claire Nee, and Helen Ingham, Car Theft: The Offender's Perspective, Home Office Research Study No. 130, HMSO, London, 1992

29Ronald V. Clarke, Thefts Of and From Cars in Parking Facilities, U.S. Department of Justice, Office of Community Oriented Policing Services, Problem-Oriented Guides for Police Series, No. 10, 2002, pp.24

30Marcia Biederman, "A Sign of the Times: No More Signs," New York Times, Feb. 16, 2001

31supra n.25

32supra n.30

33For an example of this effect, see Samuel Peltzman, "The Effects of Automobile Safety Regulation," Journal of Political Economy Vol. 83 (August 1975), pp. 677-725 (where Peltzman argues that drivers with seatbelts, knowing that they have a greater margin of safety, drive faster and less carefully.)

34Patrick Cooke, "Noises Out: What it's doing to you" New York Magazine, Nov. 2, 1992