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The Office of Motor Carrier and Highway Safety: An Analysis-Driven Organization Volume 4, No. ii   August 1999

 

In This Issue
Dale Sienicki, Editor
dale.sienicki@fhwa.dot.gov
MCSAFE is a recurring publication of OMCHS’s Data Analysis Division. It is intended to provide OMCHS staff and other stakeholders in the motor carrier and highway safety environment with descriptive statistics and analyses about traffic crashes involving commercial motor vehicles and the programs and countermeasures OMCHS has implemented to promote motor carrier and highway safety. 

About This Issue

The Office of Motor Carrier and Highway Safety’s Data Analysis Division annually surveys motor carriers that employ CDL drivers to measure the percentage of drivers who test positive for drugs and/or alcohol. The information is used by the Administrator to evaluate the FHWA’s required minimum testing rates for alcohol and drugs. The 1997 survey is discussed in this issue (Go to Article).

Other highlights of this issue include: a look at the OMCHS fact sheet on construction and maintenance work zone safety (Go to Article); a summary of information from the OMCHS publication Large Truck Crash Profile: The 1997 Picture (Go to Article); and an overview of 20-year fatal crash trends (Go to Article).

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Results from the 1997 Drug and Alcohol Survey

The Data Analysis Division of the Office of Motor Carrier and Highway Safety (OMCHS, HMIA-20) annually conducts a survey to measure the percentage of drivers with commercial driver’s licenses (CDLs) who test positive for controlled substances (henceforth referred to as “drugs”) and/or alcohol in random and nonrandom (pre-employment, post-crash, and reasonable suspicion) testing. This article reports on the 1997 survey.

All motor carriers that employ drivers with CDLs are required to have drug and alcohol testing programs. Each year, such carriers must randomly test 10% of their CDL drivers for alcohol and 50% of their CDL drivers for drugs. In addition, FHWA requires that motor carriers perform nonrandom drug and alcohol testing in cases where (1) the driver is being considered for employment (only for drugs and only when the driver has not recently been in a drug and alcohol testing program); (2) the driver has been involved in a crash (only when the crash involves a fatality, or when the CDL driver receives a citation in a towaway- or injury-related crash); or (3) the CDL driver is suspected by a supervisor of using drugs or alcohol while at work.

In the case of alcohol, a driver is considered to have tested positive if the blood alcohol content is 0.04 grams per 210 liters of breath, or higher. For drugs (marijuana, cocaine, opiates, amphetamines, and PCP) the cutoff levels for identifying use are based on guidelines set by the U.S. Department of Health and Human Services.

The positive usage rates developed by the survey and presented below represent weighted statistical estimates. These estimates are generalizable to the entire population of CDL drivers in the national fleet and have been derived using standard statistical techniques applicable to stratified samples. It is important to keep in mind that rates obtained from these procedures do not represent “true values,” but rather unbiased estimates of the true rates, with associated sampling errors.

Results

Estimates of positive usage rates from both random and nonrandom testing are discussed separately below and presented in Table 1 (drugs) and Table 2 (alcohol). The tables also include estimates from the 1995 and 1996 surveys.

Random Testing

For the 1997 survey, data collection forms were sent to 4,008 randomly selected motor carriers; 2,941 of the forms were completed and returned to OMCHS, resulting in usable drug testing data from 1,462 motor carriers (comprising 228,138 CDL drivers), as well as usable alcohol testing data from 1,294 motor carriers (comprising 112,730 CDL drivers). Respondents with non-usable data represent entities that are out of business, exempt, have no testing program in place, or belong to consortia that did not test any drivers for the motor carrier during 1997. Based on these respondents, the OMCHS estimates from random testing are as follows:

  • Drugs: The estimated positive usage rate for drugs is 1.3%. The 95% confidence interval for this estimate ranges from 1.0% to 1.6%. Thus, if the survey were to be replicated, it would be expected that this estimate would fall within this range in 95 out of 100 surveys. For 1996, this same rate was estimated to be 2.2%. Based on the levels of precision achieved for these two survey years, the decrease from 1996 to 1997 is statistically significant—i.e., the measured difference in the two rates is real and not attributable to the randomness of the samples.

  • Alcohol: The estimated positive usage rate for alcohol used, based on random testing in 1997, is 0.2%, with a 95% confidence interval ranging from zero to 0.4%. For 1996, the estimate was the same.

Nonrandom Testing

Estimates of positive usage rates from nonrandom drug testing are shown in Table 1. Rates from nonrandom alcohol testing are shown in Table 2. With the possible exception of preemployment and post-crash (nonfatal) drug and alcohol testing, the sample sizes achieved in the survey for the various non-random testing categories are much lower than those achieved for random testing. As a result, the estimated precision level of many of these estimates is low. Given the achieved levels of precision in the 1996 and 1997 estimates, year-to-year differences in non-random testing rates between these two years cannot be shown to be statistically significant.

In cases where the estimated rate in the table is zero and the standard error is missing, no drivers in the sample tested positive for the particular category. In such cases, the actual positive rate for the population is, in all likelihood, greater than zero, but the sample size was inadequate to produce a more precise estimate.

Table 1
Estimates of Random and Nonrandom Drug Usage Rates for 1995, 1996, and 1997
Category  1995 Estimate  1995 Standard Error  1996 Estimate  1996 Standard Error  1997 Estimate  1997 Standard Error 
Random Testing 2.8% 0.5% 2.2% 0.4% 1.3% 0.16%
Nonrandom:
Pre-employment 3.0% 0.3% 2.4% 0.3% 2.0% 0.15%
Post-Crash Nonfatal 4.2% 1.0% 3.9% 1.6% 5.5% 2.2%
Post-Crash Fatal * 0.6% * 47.0% * 0.02%
Reasonable Suspicion 25.0% 11.0% * 92.0% * 6.9%
Return to Duty 1.0% 0.3% * 8.1% 0.2% 0.08%
Followup 4.0% 1.5% * 6.7% * 1.9%
* Indicates extremely low precision.

Table 2
Estimates of Random and Nonrandom Alcohol Usage Rates for 1995, 1996, and 1997
Category  1995 Estimate  1995 Standard Error  1996 Estimate  1996 Standard Error  1997 Estimate  1997 Standard Error 
Random Testing 0.14% 0.02% 0.2% 0.03% * 0.1%
Nonrandom:
Pre-employment * 5.0% * -- * 0.005%
Post-Crash Nonfatal * 0.2% * 0.2% 0.01% 0.004%
Post-Crash Fatal * -- * 1.2% * 0.01%
Reasonable Suspicion 34.0% 3.0% * 19.0% * 7.8%
Return to Duty 0.4% 0.3% * -- * --
Followup 0.1% 0.1% * 0.2% * 0.015%
* Indicates extremely low precision.

For more information about the OMCHS drug and alcohol surveys, contact Richard Gruberg at (202) 366-2959 or Terry Shelton at (202) 366-1861.

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Graphic of a truck and bus with the globe behind them and pictures of the American, Canadian, and Mexican flags

1998 IHTS Week: June 1999 Update

The January 1999 issue of the MCSAFE newsletter presented readers with up-to-date summarized results of 1998’s International Highway Transportation Safety (IHTS) Week inspection activities. Additional data, reflecting complete Canadian jurisdictional results during the June 1-6, 1998 operation, have become available to the editor and are summarized in the table below.

1998 Canadian IHTS Week Level 1 Inspection Activities
Jurisdiction  Trucks Inspected  Trucks OOS  % Trucks OOS  Pass Trucksa  OOS Rate (Including Pass Trucks)b  Trucks Towed Awayc  % Trucks Towed  Driver OOS  % Driver OOS 
British Columbia 986 201 20 350 15 42 4 21 2.1
Alberta 755 163 22 525 13 30 4 28 3.7
Saskatchewan 311 57 18 90 14 32 10 15 4.8
Manitoba 444 87 20 137 15 45 10 6 1.4
Ontario 2,824 814 29 2,363 16 46 2 23 0.8
Quebec 1,001 258 26 0 26 20 2 27 2.7
New Brunswick 314 59 28 20 25 0 0 3 1.4
Prince Edward Island 25 3 12 4 10 1 4 1 4.0
Nova Scotia 616 79 13 27 12 79 13 0 0.0
Newfoundland 200 40 20 28 18 23 12 5 2.5
Yukon Territory 107 27 35 39 18 21 20 3 2.8
Northwest Territories 93 20 22 71 12 13 14 3 3.2
Canadian Totals 7,576 1,808 24 3,654 16 352 5 135 1.8
aTrucks that would have been inspected had they not had valid Commercial Vehicle Safety Alliance (CVSA) decals.
bOOS Rate when “pass trucks” are included.
cTrucks towed away or requiring repairs by mechanic before leaving site.

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Construction and Maintenance Work Zone Safety

A work zone crash is a motor vehicle traffic crash occurring in the vicinity of highway construction, highway maintenance, or utility work.

The safe and efficient flow of traffic through construction and maintenance work zones is of major concern to the Office of Motor Carrier and Highway Safety (OMCHS). This issue impacts all four major focus areas of OMCHS: running off the road; motor carrier safety; pedestrian safety; and speed management. Understanding how, where, and when work zone crashes occur will assist OMCHS in creating effective countermeasures to prevent these crashes in the future.

OMCHS has prepared a fact sheet containing descriptive statistics for work zone motor vehicle crashes. The two tables at the right exemplify the information available in the fact sheet.

As shown in Table 1, over the past 5 years the number of people killed in motor vehicle crashes in work zones has gone from a high of 828 in 1994 to a low of 658 in 1997, averaging 751 per year. In 1997, 658 fatalities resulted from motor vehicle crashes in work zones—about 2% of total fatalities (42,013).

As shown in Table 2, 171 fatalities resulted from large truck crashes in work zones in 1997—about 3% of fatalities in large truck crashes (5,355). Twenty-six percent of work zone fatalities in 1997 resulted from large truck crashes (171 out of 658). From 1993 to 1997, an average of 191 people were killed in fatal large truck motor vehicle crashes in areas designated as work zones, from a high of 221 deaths in 1994 to a low of 171 deaths in 1997. On average from 1993 to 1997, 16% of the fatalities resulting from crashes in work zones were nonmotorists (pedestrians, bicyclists, etc.). Similarly, in large truck work zone crashes during the same time period, 16% of the fatalities were nonmotorists.

Statistics presented in the fact sheet for fatal crashes are derived from the National Highway Traffic Safety Administration’s (NHTSA) Fatality Analysis Reporting System. Descriptive statistics for nonfatal crashes are derived from NHTSA’s General Estimates System.

Table 1
Fatalities in Work Zone Crashes by Person Type, 1993-1997
Person Type 1993 1994 1995 1996 1997 5-Year Average
Motor Vehicle Occupant 647 700 652 584 567 630     (84%)
Nonmotorist 117 128 137 133 91 121     (16%)
Total 764 828 789 717 658 751   (100%)
Source: National Highway Traffic Safety Administration, Fatality Analysis Reporting System.

Table 2
Fatalities in Large Truck Work Zone Crashes by Person Type, 1993-1997
Person Type 1993 1994 1995 1996 1997 5-Year Average
Truck Occupant 26 23 21 23 16 24     (12%)
Other Vehicle Occupant 137 165 151 128 135 137     (72%)
Nonmotorist 41 33 29 25 20 31     (16%)
Total 204 221 191 176 171 191   (100%)
Source: National Highway Traffic Safety Administration, Fatality Analysis Reporting System.

Copies of the Work Zone Crashes Fact Sheet may be obtained by contacting Ms. Sheila Robinson of the OMCHS Data Analysis Division (HMIA-20) at (202) 366-8593.

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Truck Crashes in 1997: A Summary

In September 1998, the OMCHS Data Analysis Division published Large Truck Crash Profile: The 1997 National Picture. This document contains descriptive statistics about fatal and nonfatal (injury and property-damage-only) large truck crashes that occurred in 1997. The following summarizes some of the information contained in the national profile. Please note that since the publication of the national profile, the 1997 FARS data file has been updated. In some cases, the numbers appearing in this article differ from those published in the profile.

  • In 1997 there were 4,917 large trucks involved in fatal crashes. There were also an estimated 97,000 large trucks involved in injury crashes, and 342,000 involved in property-damage-only crashes.

  • Large trucks in 1997 accounted for 9% of the vehicles involved in fatal crashes, 2% of those involved in injury crashes, and 4% of the vehicles involved in property-damage-only crashes.

  • In 1997, 63% of trucks involved in fatal crashes and about 50% of those involved in nonfatal crashes were tractors pulling single semi-trailers. Four percent of the trucks involved in fatal crashes were doubles, and 0.3% were triples. Less than 5% of trucks involved in fatal and nonfatal crashes were transporting hazardous materials.

  • The crash rate (number of crash-involved vehicles per 100 million vehicle miles traveled) for large trucks in fatal crashes is 2.5, slightly higher than the rate for passenger vehicles (2.1). The crash rate for passenger vehicles involved in injury crashes, however, is more than three times the rate for large trucks: 172 vs. 51.

  • In two-vehicle fatal crashes between a large truck and a passenger vehicle, 7% of the truck drivers were under 26 years old, and only 2% of the truck drivers were over 65. In contrast, 24% of the passenger vehicle drivers in these crashes were under 26 years old, and 20% were over 65.

  • In two-vehicle fatal crashes between a large truck and a passenger vehicle, less than 1% of the truck drivers had a blood alcohol content (BAC) of 0.10 grams per deciliter or greater, the level for intoxication in most States. In contrast, 15% of passenger vehicle drivers in these fatal crashes with a truck had a BAC level of 0.10 or greater.

  • Driver-related crash factors were coded for 28% of truck drivers involved in a fatal crash with a single passenger vehicle. However, driver-related crash factors were coded for 80% of the passenger vehicle drivers involved in these crashes.

  • A large majority of 1997 fatal and nonfatal truck crashes occurred in good weather, on a dry road surface, during the day, and on a weekday.

  • The first harmful event in 78% of fatal large truck crashes was the collision of the truck with another moving vehicle. About half of the first crash events for trucks involved in nonfatal crashes were collisions with another moving vehicle.

  • None of the data above addresses crash causation or fault. Thus, the data can only be suggestive as to the reasons for truck crashes.

For a copy of the complete Large Truck Crash Profile: The 1997 National Picture, call Lisa Harris at (202) 366-1861. To view the profile on the World Wide Web, go to: fhwa.dot.gov/omc/omchome, and click on “News and Events.” The profile is listed under this section in PDF format.

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Overview of 20-Year Fatal Crash Trends

The data table and graphs below show 20-year trend data for fatalities and fatal crashes involving large trucks. Table 1 and Figure 1 show 20-year trend data (1978-1997) reflecting fatalities in crashes involving large trucks, large trucks involved in fatal crashes, and fatal crashes involving large trucks:

  • From 1978 to 1997, the number of fatalities in crashes involving large trucks has dropped by 15.1%; the number of large trucks involved in fatal crashes has dropped by 14.6%; and the number of fatal crashes involving large trucks has also dropped by 14.6%.

  • Over the 20-year period, the average number of fatalities in crashes involving large trucks annually was 5,464; the average number of large trucks involved in fatal crashes annually was 4,948; and the average number of crashes involving large trucks annually was 4,652.

Figure 2 shows 20-year trend data reflecting fatalities in crashes involving large trucks per 100 million vehicle miles traveled. The rate has dropped by 53.3%, from 6.0 in 1978 to 2.8 in 1997.

Table 1
Large Truck Fatal Crash Statistics, 1978-1997
Year Fatalities
in Crashes
Involving Large Trucks		 Large Trucks
Involved in
Fatal Crashes		 Fatal Crashes
Involving
Large Trucks
1978 6,356 5,759 5,405
1979 6,702 6,084 5,684
1980 5,971 5,379 5,042
1981 5,806 5,230 4,928
1982 5,229 4,646 4,396
1983 5,491 4,877 4,615
1984 5,640 5,124 4,831
1985 5,734 5,153 4,841
1986 5,579 5,097 4,785
1987 5,598 5,108 4,813
1988 5,679 5,241 4,885
1989 5,490 4,984 4,674
1990 5,272 4,776 4,518
1991 4,821 4,347 4,097
1992 4,462 4,035 3,825
1993 4,856 4,328 4,101
1994 5,144 4,644 4,373
1995 4,918 4,472 4,194
1996 5,142 4,755 4,413
1997 5,398 4,917 4,614
Sources: Vehicle Miles Traveled—Federal Highway Administration;
Fatalities, Fatal Crashes, and Vehicles Involved—National Highway Traffic Safety Administration,
Fatality Analysis Reporting System (1978-1997).

Figure 1
Large Truck Fatal Crash Statistics, 1978-1997
Large Truck Fatal Crash Statistics, 1978-1997 D

Figure 2
Large Truck Fatality Rate, 1978-1997
Large Truck Fatality Rate, 1978-1997 D

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For More Information . . .

Information Sign Information on large truck and motor coach crashes and the nature and effectiveness of the Office of Motor Carrier and Highway Safety's safety programs is available from:
    The Office of Motor Carrier and Highway Safety
    Data Analysis Division (HMIA-20)
    400 Seventh Street, SW
    Washington, D.C. 20590
HMIA-20 has designated four “Data Analysis Coordinators” to assist field staff with data analysis inquiries; in their absence, inquiries may be directed to any other member of the HMIA-20 staff at (202) 366-1861. Faxes may be sent to: (202) 366-8842.
 
Employees operating in the States 
served by the Eastern Resource Center
should contact Richard Gruberg,
(202) 366-2959.		 Phone Rings
Phone Chat Employees operating in the States 
served by the Southern Resource Center
should contact Ralph Craft,
(202) 366-0324.
Employees operating in the States 
served by the Midwest Resource Center
should contact Chuck Rombro,
(202) 366-5615.		 Hang-Up Smile
Phone Smile Employees operating in the States 
served by the Western Resource Center
should contact Dale Sienicki,
(202) 366-9039
Fax: (413) 771-0241.

To obtain assistance
in the application and interpretation of statistics, please call Richard Gruberg, 
(202) 366-2959. 

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