How Effective Are Street and Alley Closures?

You may have read newspaper reports about successful street closures in particular neighborhoods, or heard about them from police officers involved. Crime may indeed have been reduced, but you should always be wary of anecdotal evidence of this kind. People like to think their projects were successful, and newspapers like to publish feel-good stories about communities pulling together to defeat crime. While you can learn much from these accountsfor example, how to overcome the difficulties associated with street closuresresearch studies generally provide more reliable evidence on effectiveness.

Unfortunately, only a relatively small number of projects involving street closures have been evaluated (f or example, no published evaluations exist of substantial street-closure schemes in Dallas; Houston; Chicago; Bridgeport, Conn.; and Oakland, Calif.)9 and the studies that have been published tend to focus on successful projects, simply because studies of unsuccessful projects are less likely to be published. Furthermore, not all research studies on street closures are well designed. Properly designed studies compare the neighborhoods crime rates before streets were closed with crime rates after they were closed. They should also compare the neighborhoods crime rates with those of nearby control areas where streets were not closed. This helps to rule out alternative explanations for drops in crime, such as seasonal changes, intensified police enforcement, or reduced gang activity. The studies sometimes collect other data that help in evaluating street closings, including information regarding the number of service calls, the volume of traffic, the residents perceptions of security, and the costs of installing gates or barriers. In some cases, evaluations also examine whether crimes prevented by the closures have been displaced to nearby locations.

This section summarizes the information available from 11 studies that evaluated street or alley closings. There is considerable variety among the projects reviewed. Several were undertaken in deprived inner-city neighborhoods, plagued by a variety of crimes. Three other projects were citywide efforts, one undertaken in an affluent Florida city. Three overseas projects focused on street prostitution. Only one (British) project specifically focused on closing alleys, though in other projects, both alleys and streets were closed. City governments and residents associations implemented most of the projects, though often with considerable police involvement.

Despite the variety of areas and crimes covered, for some crimes and for some settings, there are no directly relevant studies to draw upon. This means the studies may not tell you whether closing streets or alleys will work in your particular situation. This is not unusual, because there are important gaps in knowledge about effectiveness for nearly every aspect of policing, from patrol through criminal investigation. In fact, research almost never tells you exactly what to do in a given situationit can only help you select responses that have a better chance of working for you. It is down to you to judge the fit between the available research and your own situation.

Table 1 summarizes the main features of the studies, including the type of area covered, the crimes targeted, and the results achieved (the Appendix provides fuller descriptions of the studies). Few of the studies are recent. Only one projectthat undertaken in Charlotte, N.C. was specifically designed as a police-led problem-oriented project, though police were active partners in the other projects. In the past 10 years, projects submitted for the Herman Goldstein Award for Excellence in Problem-Oriented Policing have frequently included closures, but deal only with problems in shopping plazas and other commercial facilities,10 and problems relating to festivals and other events.11

Even though few of the studies in Table 1 are problem-oriented projects, you can still learn from themparticularly about the effectiveness of the closures. To help you decide how much weight to place on each study, Table 1 includes ratings of the research designs quality: weak, adequate, or strong. You will see that several of the studies are rated as weak, and you should be aware that even those rated as adequate or strong have their limitations. Few of them can separate the effects of street or alley closings from those of other measures taken at the same time, and few examine the effects on crime or disorder for more than a year. This means that little is known about street closures long-term effects.

Judged by the strictest criteria, none of the studies would be considered strong because none of them included randomly selected streets to be closed. However, this would very rarely be possible, and the studies must be judged against more realistic criteria. In these assessments, an informal (probably generous) judgment was made, taking account of the number of streets closed, the crime measures used, the level of crime before intervention, the time period studied, whether control areas were studied, whether displacement/diffusion was measured, and whether costs were calculated. No criticism of the researchers is implied by these ratings, since they were generally doing the best they could, given the practical constraints and the time and funds available.

Table 1 : Evaluated Projects Using Street and Alley Closures
	City	Type of Area	Year(s)	Targeted Offenses	No. of Streets Closed	Other Actions	How Effective?	Research Design*	Studies
1	Hartford , Conn.	Declining inner-city neighborhood (Asylum Hill)	1973	Burglary, mugging, purse-snatching	Four	Residents associations established; neighborhood policing scheme	Closures reduced crime, but effect only temporary. Fear of crime reduced.	Adequate	Fowler, McCalla, and Mangione (1979)[Full text ]; Fowler and Mangione (1982) [Full text ]
2	Dayton , Ohio	Transitional neighborhood (Five Oaks)	1992	Drug houses, gunshots, prostitution, gangs, burglary, speeding	35 streets, 26 alleys	Supportive residents association; high level of media attention	Crime reduced by 25 percent within one year; violent crime reduced by 40 percent. No evidence of displacement. Concern about crime decreased. Traffic declined by 36 percent.	Strong	Dayton Office of Management and Budget (1994); Donnelly and Kimble (1997)
3	Los Angeles	Crime-ridden, inner-city neighborhood ( Newtown)	1990	Gangs, drug dealing, assault, homicide, drive-by shootings	14	Increased police patrols; community policing	Serious crimes immediately reduced, including homicides and drive-by shootings. Crimes increased when streets reopened.	Strong	Vernon and Lasley (1992); [Full text ] Lasley (1998) [Full text ]
4	Hartford , Conn.	Public- housing project	About 1997	Drug dealing, assault, drive-by shootings	One	None	Violent crime reduced, with no displacement. Drug dealing unaffected.	Weak	Zavoski et al. (1999)
5	Charlotte , N.C.	Inner-city, drug-dealing neighborhood( Belmont)	2000	Drug dealing, violence	Two	None	Substantial reduction in violence in the area immediately affected by the closures. Violence was not displaced, but drug activity may have been.	Adequate	Markoe (2000 )
6	Finsbury Park, London	Run-down, inner-city neighborhood with long- established street prostitution	1985	Street prostitution and cruising johns	Seven	Police crackdown on prostitutes, pimps, and johns; hotels and landlords prosecuted	Large reduction in street prostitution and cruising. Lower rates of auto theft, assault, and burglary. Resident satisfaction increased. Surprisingly little displacement.	Strong	Matthews (1997)
7	Streatham, London	Middle-class, residential area with a recent problem of street prostitution	1989	Street prostitution and cruising johns	Several streets closed and no entry signs	Police crackdown on prostitutes and cruising johns; police antiburglary initiative	Large reduction in street prostitution, cruising, burglary, and other crimes. Increased resident satisfaction. Prostitutes displaced from residential area.	Strong	Matthews (1993) [Full text ]
8	Vancouver , British Columbia	Downtown prostitution strolls	1981	Street prostitution and cruising johns	Seriesof diverters installed	Series of other initiatives taken at different times in the same areas	The hardened, drug-addicted prostitutes adapted by displacing to nearby areas. The barriers also reportedly helped prostitutes to solicit cruising johns, who were forced to slow down.	Weak	Lowman (1992)
9	St. Louis	Racially integrated, 60-block city neighborhood	1984	UCR offenses	Multiple	Target- hardening; lighted porches; neighborhoodwatch; community crime newspaper	Lower rates of increases in burglary up to five years after closures. Limited impact on fear.	Adequate	Wagner (1997)
10	Liverpool , England	Residential neighborhoods with row houses and rear alleys	2000 to2003	Burglary	3,168 alley gates installed	Research design focused only on alley gates	Burglary reduced by 37 percent within one year. Little displacement, but diffusion of benefits. Gates were highly cost- effective.	Strong	Bowers, Johnson and Hirschfield (in press)
11	Miami Shores , Fla.	Affluent suburban city	1988 to1991	Robbery, burglary, larceny, aggravated assault, auto theft	67 in first phase; eight in second phase	None	Burglary, larceny, and auto theft reduced. Lower rates of increases in robbery and assault, compared with nearby jurisdictions.	Weak	Atlas and LeBlanc (1994)

The incomplete coverage of the research, the limitations of the methodology, and some inconsistencies in the results have been discussed above. Even so, one can draw some broad conclusions about the street and alley closures, summarized as follows:

• Street closures have been used for many years in the United States and elsewhere as a method of preventing crime. Only a small number of projects have been evaluated. Those with positive results are more likely to be reported.
• Street closures are usually introduced along with other measures (such as crackdowns, neighborhood watch, and target-hardening), and it can be difficult to separate the effects of street closures from those of other measures. Nevertheless, most of the evaluations conclude that street closures have reduced crime and disorderin some instances, quickly and dramatically. The crimes reduced include robbery, burglary, prostitution, drug dealing, assault, and drive-by shootings.
• Street closures have been judged effective in a variety of different settingsinner-city residential neighborhoods, downtown areas, prostitution strolls, and affluent areas abutting poorer ones.
• Little is known about the long-term benefits of street closures, though one study reported that the benefits were only temporary.
• Even when closures have been found effective, streets have sometimes been reopened as a result of pressure from the local community.

Though residents and police believed the 1993 street-closure scheme in the Hispanic East Side of Bridgeport, Conn., had been effective in reducing drug dealing and other crimes, the city council ordered that the barriers be removed in 1998, in response to residents complaints. Many had become tired of the inconvenience caused by the 40 street closures, and they also believed that the ugly concrete barriers stigmatized the neighborhood and scared off businesses (Halbfinger 1998).

• In some cases, barriers have been said to facilitate crime. They can slow cars down, enabling prostitutes or drug dealers to solicit customers. They can also trap unwary motorists who stray into dangerous neighborhoods.
• Little research is available on the effect of gating alleys behind properties, but one exceptionally strong study found that gating brought about large reductions in burglary.
• Street and alley closures typically cause little displacement of crime. In some cases, the benefits of street closures can spread beyond the closure area (a phenomenon researchers call diffusion of benefits).
• Little is known about the cost-effectiveness of street closings. One study of alley closures found them to be highly cost-effective. Within one year, the savings from burglaries prevented were much greater than the costs of installing the gates.

In conclusion, research has shown that street and alley closures can reduce crime in a variety of different settings. However, research is absent or sparse for some crimes and settings. In addition, the studies do not separate the benefits of closures from those of other measures taken at the same time. Follow-up is typically short, and little is known about the long-term benefits of street and alley closures. Finally, the studies provide little information about whether the savings in crime outweigh the costs of the closures.