Operation Safe Crossing

Contact name: 
Robert B. Voas
PhD, Psychology Senior Research Scientist
Institute for Public Strategies (IPS) San Diego
+ 1 301 755 2700
Pacific Institute for Research and Evaluation, 11710 Beltsville Drive, Suite 300Calverton, MD 20705, 3102 USA
+ 1 301 755 2799



Every weekend night, thousands of young San Diegans stream into Tijuana, Mexico, to patronize bars and nightclubs only to return early in the morning with BACs over the legal limit to drive.


To evaluate a large drunk-driving enforcement program at the US/Mexican border to reduce the number of youths crossing the border to drink in Tijuana. The integration of data collection with media advocacy is designed to achieve two objectives:

  • Enhance media coverage by providing interesting information that attracts the interest of local communities, and
  • Provide support for local police to increase resources devoted to enforcement.

Operation Safe Crossing is a project breaking new ground by forging relationships between science and community action elements to reduce drunk driving. The project uses a media advocacy process in which local leaders are used as spokespersons to release new data at news conferences.Data from a border breath-test survey were used to dramatize the problem and gain public support for action. The data were also used to help design the enforcement effort and measure progress in reducing the cross-border drinking problem.


Analysis of data involving more than 2 million pedestrians returning from Tijuana indicated that the Operation Safe Crossing program reduced the number of late-night crossers by 31.6%. Further, the number of underage drinking pedestrians significantly declined on average by 7.7 per month or 51.2%


The symbiotic relationship between media advocacy, enforcement, and science seems to be producing the desired effect. Effective use of data through media advocacy programs to support an enforcement effort can reduce alcohol-related crashes.

Intervention details

Type of intervention
Other enforcement
Problem addressed
Alcohol, Binge drinking, Vertical drinking, Underage drinking, Impaired driving, Legislation
Intervention setting
Mass Media
Target population

Underage youths aged 18-20 years and young adults aged 21-30 years residing in San Diego County.

Substances adressed
Intervention activities
Providing information
Use of media
Enforcement: breath tests
Strengthening the drinking-and-driving enforcement at and near the border:Increasing of foot patrols monitoring the pedestrian crossing area;Enforcement of law for entering bars;Each measure was supported by one or media events designed to call attention to the enforcement effort.Breath test survey at the border: Integration of data within the intervention used to help organize the program;Plan countermeasures;Support program operations and evaluate operational effectiveness.
Theory/evidence behind the intervention

Media advocacy as a purposeful use of news media to further a social policy objective (Treno & Holder, 1997). The relation between media reports, impaired driving arrests and crash reductions is well illustrated in the community trials program (Voas, Holder & Gruenewald, 1997).

Evaluation details

Activities evaluated

These include:

  • OSC enforcement and media advocacy (Measure of public awareness of the OSC)
  • Number of youths returning from a night drinking in Tijuana
  • BACs of the returnees
  • Crashes involving drink driving.
Evaluation results (Outcome evaluation)

OSC enforcement and media advocacy: About 12% more of the youthful bar-goers appeared to be aware of the new enforcement program than did their peers who did not drink in Tijuana bars. From 50% to 60% of the Tijuana bar-goers were aware of the increased enforcement.

Number of youths returning from a night drinking in Tijuana: As measured by the cumulative growth of media events, the OSC program was found to have an effect, significant beyond the 0.001 level, on the number of late-night crossers. The reduction produced by the OSC program was estimated to be 31.6%.

BACs of the returnees: During the June 1997 December 1999 period, the number of underage drinking pedestrians declined by 39.8% over the course of the survey (P < 0.01).

Had been drinking crashes: Analysis of 16-20-year-olds revealed a statistically significant, negative relationship between the cumulative media coverage function and the ratio of had-been-drinking crashes to had-not-been-drinking crashes (B = -0.002, P < 0.04). This decline reflects a 45.3% reduction in the number of 16-20-year old drivers who had been drinking and were involved in crashes (expressed as a multiple of drivers in the same age group who were not drinking and involved in crashes).

Diagnostic checks indicated that there were no significant autoregressive and moving average parameters. Results pertaining to the age group of 21-25-year-olds revealed no significant effect associated with the media intervention, indicating that the response remained constant throughout the period under analysis.

It is possible that this single, extreme data point could be driving the statistically significant reduction. To examine this possibility, analysis was conducted after eliminating the two final data points of the series. A statistically significant relationship between the media function variable and the had-been-drinking ratio was detected (B = -0.001, P < 0.04, one-tailed) even after removing the extreme data point.


Evaluation references

Robert B. Voas, A. Scott Tippetts, Mark B. Johnson, James E. Lange & James Baker (2002). Operation safe crossing: using science within a community intervention. Addiction, 97, 1205-1214.

An abstract for this journal article can be found in the HNT literature section here.