Operation Cul-de-Sac

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.

Intervention ID

No Data.


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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