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Program Profile: Operation Cul-de-Sac

Evidence Rating: Effective - One study Effective - One study

Date: This profile was posted on June 06, 2011

Program Summary

The program supports the installation of permanent traffic barriers in high-crime neighborhoods to reduce gang drive-by shootings, assaults and homicides. The program is rated Effective. The intervention significantly reduced drive-by shootings; caused predatory crime to fall 8 percent the first year and 37 percent the second year of the program; and increased student attendance by around 200 students per day at the local high school after the street closures.

Program Description

Program Goals/Target Sites

Operation Cul-de-Sac (OCDS) was designed to tackle the problem of gang violence—drive-by shootings, assault, and homicide—in high-crime areas of Los Angeles (LA), Calif. The Los Angeles Police Department (LAPD) installed traffic barriers to block access to certain streets by cars.


The LAPD looked at data on gang violence to identify neighborhoods where gang violence and homicides were high. Analysis found much of the violence stemmed from multiple gangs fighting for the same prime drug sales locations. The analysis also determined that 80 percent to 90 percent of the drive-by shootings happened on residential streets at the periphery of the community. These residential streets connected to major thoroughfares, thus providing easy exit routes. Residential streets that only connected to other minor residential streets experienced very few drive-by shootings. The police therefore targeted for closure those streets that connected to major arteries.


Program Components

The main intervention comprised street closures, although in the 1st year, this was combined with more intensive levels of street policing. OCDS was one of the first programs in the country to use street closures for crime control, and the idea developed after the accidental discovery of the effectiveness of installing sawhorses in reducing drug activity in a well-known LA drug district.


The program started in January 1990 and ran through December 1991 in a neighborhood in South Central LA. Prior to the installation of street barriers, the LAPD canvassed neighbors in the community to gauge support for the project; overall, support for the project was very high. On Feb. 1, 1990, the LAPD closed major roads leading to/from these hotspots by installing 14 temporary concrete K­–rail (freeway dividers) traffic barriers. Signs were attached that read, “Narcotics Enforcement Area.” The barriers were placed to allow for unobstructed school, business, and emergency fire traffic. Being only 3 feet tall, the barriers did not impede foot traffic.


Later, the concrete barriers were replaced with iron gates, which could be unlocked for emergency vehicles. These were 6 feet high and did impede pedestrian traffic. During the 1st year, the LAPD also implemented other community police projects, such as the assignment of 15 officers who were tasked with getting to know the residents and neighborhood; the development of task forces to remove signs of physical disorder (e.g., remove garbage or graffiti); and the creation of block clubs. Funding was reduced during the 2nd year of the program, and many of the additional community police projects were discontinued; only the traffic barriers remained in place. By 1992, most of the barriers were badly damaged, and no longer prevented vehicular access to the area.



The program was developed and implemented without any explicit reference to theory. The program design is explained well, however, by the theory of situational crime prevention, which theorizes that crime can be reduced by identifying and then eliminating the forces that facilitate would-be offenders’ criminal acts. In the case of OCDS, the police made it harder to enter and exit “hot spots” or gang territories; by doing so, police reduced the opportunity to commit drive-by shootings and elude police.

Evaluation Outcomes

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Study 1

Overall Gang Crime

Lasley (1996) found that crime fell during the 1st year of the Operation Cul-de-Sac (OCDS) program, rose (though not back to preprogram levels) in the 2nd year when some aspects of the program were withdrawn, and returned to preprogram levels after all aspects of the program were withdrawn.



There was no evidence that crime was displaced. There is some evidence of a diffusion of benefits.


Drive-By Shootings

The incidence of drive-by shootings fell significantly during OCDS, then rose after the program was discontinued.


Predatory Crime

Predatory crime (e.g., murder, rape, street robbery, aggravated assault, and purse snatch) fell 8 percent the 1st year and 37 percent the 2nd year of the program, but the drop was accounted for entirely by aggravated assault.


Property Crime

There was a drop of 31 percent in property crime, but it was unclear whether the drop was a result of the program. The comparison area experienced a similarly large drop in property crime, so it is possible that there was a diffusion of benefits from the treatment area to the comparison area, but it is also possible that there was an unexplained variable causing the drop in property crime in both areas. Moreover, the rates of property crime rose to preprogram levels during the 2nd year of operations.


School Attendance

There was an increase in attendance by around 200 students per day at the local high school (located within the OCDS program area) after the street closures.


Fear of Crime

There was qualitative support for a drop in fear of crime.

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Evaluation Methodology

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Study 1

Lasley (1996) assessed the impact of Operation Cul-de-Sac’s (OCDS) street closures on crime rates using a quasi-experimental design. The areas adjacent to the treatment area served as a control area; rates of crime in this adjacent area were also assessed to determine whether crime had been displaced outside the treatment area or whether there was a diffusion of benefits.


Data was collected from several different sources. Crime data came from official Los Angeles Police Department statistics on homicide, aggravated assault, and property crime. Four years (1989–92) of data were divided into quarters for analysis of crime levels before, during, and after program implementation. Sample sizes were small. Tests for significance were set at 5 percent (p<.05). Data was also collected from unstructured interviews (often in Spanish) with residents of the OCDS program area as well as with gang members, and school data was provided by the Los Angeles Unified School District.


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Lasley (1996) reports that at the time of installation, the cost of permanent traffic barriers was relatively low ($100 for concrete barriers; up to $2,000 for more elaborate gates). In 1990, the total cost for the construction of each gate, which included labor and materials, ranged from $1,500 to $2,000.
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Evidence-Base (Studies Reviewed)

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These sources were used in the development of the program profile:

Study 1

Lasley, James R. 1996. “Using Traffic Barriers to ‘Design Out’ Crime: A Program Evaluation of LAPD’s Operation Cul-de-Sac.” Fullerton, Calif.: California State University, Division of Political Science and Criminal Justice.

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Additional References

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These sources were used in the development of the program profile:

Lasley, James. 1998. “Designing Out” Gang Homicides and Street Assaults. Research in Brief. Washington, D.C.: U.S. Department of Justice, Office of Justice Programs, National Institute of Justice.
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Program Snapshot

Gender: Both

Geography: Urban

Setting (Delivery): Other Community Setting, High Crime Neighborhoods/Hot Spots

Program Type: Community and Problem Oriented Policing, Community Awareness/Mobilization, Community Crime Prevention , Situational Crime Prevention, Hot Spots Policing

Current Program Status: Not Active

James Lasley
California State University Fullerton
800 N. State College Blvd Office No. UH-502
Fullerton CA 92831-3599
Phone: 657.278.3401