Background

In a 1991 New York City subway crash that resulted in five deaths and about 200 injuries, the train operator was intoxicated and later found to have a blood alcohol level of 0.21, considerably higher than the legal limit for operating a motor vehicle. This tragic event, along with several other incidents, spurred a legislative process that ultimately led in 1995 to the implementation of a comprehensive program of drug and alcohol testing in most segments of the transportation industry. The regulations have implications specifically for controlling the influence of alcohol and drugs on the transit industry and potentially for controlling the influence of drugs and alcohol at worksites in general.

 

The Current Study

Data on post crash and random drug and alcohol testing results among transit industry employees from 1995–2000 were obtained from annual reports published by the US Department of Transportation. Employees who perform safety sensitive functions became subject to mandatory alcohol and drug testing, including those involved in revenue vehicle operation, maintenance, and dispatch; those with a commercial driver’s license for non-revenue vehicle operation; and armed security personnel. The regulations call for several types of testing including testing for cause and pre-employment, random, post crash, and return-to-work testing. Drugs tests are performed through urinalysis for marijuana, cocaine, opiates, amphetamines, or phencyclidine (PCP).

From 1996–2000, refusal rates for drug tests were less than 1/10 of 1% of all attempted tests (drug refusal rate for 1995 not available). For alcohol testing, the refusal rate from 1995–2000 ranged from 0.10% to 0.24% of all attempted tests. The penalty for testing refusal is immediate removal from duty. An employee who fails a drug test is immediately removed from their safety sensitive position, informed of available education and treatment programs, and is referred to a substance abuse professional to determine whether the employee has a drug problem.

 

Study Findings

The proportion of transit employees who tested positive in random or post crash alcohol 1n 1995-2000 was extremely small, ranging from 0.0004 to 0.0020, and from 0.0010 to 0.0017, respectively. Based on these results, crash risks were calculated for 1995 and 1999. Less than one crash per 1000 might have been due to alcohol for either year.

A greater proportion of employees tested positive for random and post crash drug use compared to alcohol, though the number of positive tests was still extremely small. The proportion testing positive for post crash and random drug testing ranged from 0.0095 to 0.0217. The 1995 proportion of 0.0217, for example, represents about 22 positives for each 1000 post crash tests, and 0.0173 represents about 18 positives for each 1000 random tests. The number of crashes that might have been due to drug use per 1000 crashes from 1995–2000 ranged from 3.8 in 1998 to 6.7 in 1997.

Based on the proportion of positive alcohol or drug tests and the number of transit crashes each year, the estimated number of crashes that might have been due to either alcohol or drugs ranged from 91 in 1998 to 167 in 1997.

 

Conclusions

This study indicates that alcohol and drug use appear to be quite low among transit employees. The degree to which this low level of use is due to the knowledge that random and post crash tests for drugs and alcohol take place is unknown.

 

The Take-Home Message

The consequences of a transit crash can be extremely serious. There are many potential causes of crashes that are more likely than drug or alcohol use given the current low use rates among transit workers. Greater attention to these risks has a greater probability of improving safety.

 

Reference

Attributable risk of alcohol and other drugs for crashes in
the transit industry
C B Cunradi, D R Ragland, B Greiner, M Klein, J M Fisher
Injury Prevention 2005;11:378–382. doi: 10.1136/ip.2004.007476

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