Researcher

This study was performed by

Decision Research, Santa

Barbara, California; and Essex

Corporation, Goleta, California;

Contract No. DTFH61-89-C-096.

Distribution

This Tech Brief is being distributed according to a standard

distribution. Direct distribution

is being made to the Resource

Centers and Divisions.

Availability

The study final report will be

available from the National

Technical Information Service,

Telephone: (703) 605-6000.

Key Words

truck driver, fatigue, alertness,

commercial motor vehicle 

drivers, shift workers, driver,

countermeasures, work habits,

sleep habits, survey.

Notice

This Tech Brief is disseminated

under the sponsorship of the

Department of Transportation

in the interest of information

exchange. The Tech Brief 

provides a synopsis of the

study’s final publication. The

Tech Brief does not establish

policies or regulations, nor

does it imply FHWA endorsement of the conclusions or 

recommendations. The U.S.

Government assumes no 

liability for its contents or 

their use.

Alertness Maintenance 

Drivers employ a variety of methods and activities for maintaining alertness while 

driving. Some of these include: 

• cooling the truck cab • drinking coffee 

• stretching • eating 

• listening to AM/FM radio • using tobacco products 

• talking on CB • singing 

No single activity stands out as being significantly more effective for maintaining 

alertness than others. However, drivers reported that the most effective group of 

activities included cooling the air by air conditioning or opening windows, stretching 

or changing sitting positions, and listening to the radio or tapes. 

Other options for maintaining alertness while driving include the use of controlled 

substances. Interviewers questioned drivers about the use of such substances by other

drivers known to the respondent. The large majority of drivers interviewed said that

none of the drivers known to them used alertness aids such as speed or cocaine, or

relaxants in the form of marijuana or sleeping pills. Seventy percent of the surveyed

drivers responded that at least some of the drivers they knew used alcohol to relax, 

but nearly a third indicated that none of the drivers known to them use alcohol. 

Most people having conventional jobs arrive at their places of employment not too

long after they awake and begin working in a relatively refreshed state. Because of 

the nature of their employment, however, truckers are often awake for a longer 

period of time, and may already be somewhat fatigued before beginning their job.

Nearly half (44.6 percent) of the drivers reported that they had been awake for 6 or

more hours before beginning their current trip. The elapsed time between waking 

and beginning to drive was most often due to work-related causes, such as waiting 

for a dispatcher to call, or loading and unloading a vehicle. 

Further Research 

These survey results have highlighted the problem of CMV driver fatigue and, in 

particular, have indicated that driver drowsiness episodes are common in long-haul

commercial driving. Since the completion of this study, the FHWA has continued to

implement its comprehensive program of research, technology development, 

rulemaking, education/outreach, and enforcement relating to fatigue and hours of 

service. Numerous specific questions, issues, and opportunities are being addressed. 

In the area of rulemaking, the FHWA is currently in the process of changing the 

60-year-old driver hours-of-service rules; one priority in this rulemaking will be to give

drivers better opportunities for sufficient daily sleep. In research and technology, the

FHWA is performing research on specific operational issues such as sleeper berths,

local/short haul driving, and loading/unloading, as well as supporting research to 

develop technologies that may aid in fatigue management and self management by

drivers. One facet of this work involves in-vehicle systems to continuously assess driver 

alertness based on performance and/or psychophysiological arousal and provide 

feedback to drivers to encourage sufficient rest and sleep.

February 1999

Publication No. FHWA-MCRT-99-006
inspection sites with drivers who were willing and

qualified. A qualified driver was one who was driving

a loaded tractor-trailer combination, had driven at

least 60,000 miles during the last year, and had been

on the road at least 24 hours prior to the interview. 

Results 

Researchers completed a total of 511 interviews. 

Table 1 shows the number of participants and refusals

at each location. The relatively large number of

refusals in Georgia may have been due to the level of

inspection performed at that site. At the Georgia

inspection site only weight and license checks were

conducted, not requiring drivers to stop for an

extended amount of time. Hence, many drivers

declined to stop for the interview. 

Driver and Job Characteristics 

Participating drivers were predominantly male (96.5

percent) and ranged in age from 22 to 67 years, but

the mean and median ages were virtually the same

(42 and 43 years, respectively). 

Nearly one-third of the drivers (31.5 percent) were

owner-operators. One in twenty (5.3 percent)

responded that they were union members. The large

majority of respondents stated that they usually

drove irregular routes and had working hours that

varied from day to day. Driver and job characteristics

for all four interview sites are presented in table 2.

Sleeping Habits 

Sleep is the most fundamental requirement for driver

alertness. For this reason, many of the questionnaire

items pertained to the sleep habits of drivers. 

To feel totally rested, the large majority of drivers

(76.7 percent) reported that they needed between 

6 and 8 hours of sleep, with an average of 7 hours. 

Of the drivers interviewed, 91 percent responded 

that while on the road, they usually took their main

sleep in the sleeper berth. An additional 6.7 percent

reported that they usually slept in motels. Threequarters of the drivers who used the berth usually

took their sleep in one stretch and most of them

reported spending 8 to 9 hours in the berth. In 

contrast, more than two-thirds of those drivers who

split their rest periods usually spent 4 to 5 hours in

the berth at one time. Further examination of these

data revealed that drivers who split their rests tended

to sleep fewer hours than those who rested in one

stretch. Table 3 presents the amount of time solo and

team drivers typically spend in the sleeper berth. 

Table 2. 

Driver and job characteristics.

Characteristic Total California Georgia Missouri Virginia

Base for Percent 511 129 124 128 130

Owner-Operator 31.5% 23.3% 23.4% 25.0% 53.8%

Union Member 5.3% 4.7% 4.8% 5.5% 6.2%

Irregular Route 84.1% 74.4% 83.9% 88.3% 89.2%

Variable Hours 84.7% 84.5% 83.1% 82.0% 89.2%

Drive Solo 84.1% 82.9% 86.3% 79.7% 87.7%

Table 1. 

Distribution of interviews and refusals by location.

Total California Georgia Missouri Virginia

Interviews 511 129 124 128 130

Refusals 241 7 146 19 69
inspection sites with drivers who were willing and

qualified. A qualified driver was one who was driving

a loaded tractor-trailer combination, had driven at

least 60,000 miles during the last year, and had been

on the road at least 24 hours prior to the interview. 

Results 

Researchers completed a total of 511 interviews. 

Table 1 shows the number of participants and refusals

at each location. The relatively large number of

refusals in Georgia may have been due to the level of

inspection performed at that site. At the Georgia

inspection site only weight and license checks were

conducted, not requiring drivers to stop for an

extended amount of time. Hence, many drivers

declined to stop for the interview. 

Driver and Job Characteristics 

Participating drivers were predominantly male (96.5

percent) and ranged in age from 22 to 67 years, but

the mean and median ages were virtually the same

(42 and 43 years, respectively). 

Nearly one-third of the drivers (31.5 percent) were

owner-operators. One in twenty (5.3 percent)

responded that they were union members. The large

majority of respondents stated that they usually

drove irregular routes and had working hours that

varied from day to day. Driver and job characteristics

for all four interview sites are presented in table 2.

Sleeping Habits 

Sleep is the most fundamental requirement for driver

alertness. For this reason, many of the questionnaire

items pertained to the sleep habits of drivers. 

To feel totally rested, the large majority of drivers

(76.7 percent) reported that they needed between 

6 and 8 hours of sleep, with an average of 7 hours. 

Of the drivers interviewed, 91 percent responded 

that while on the road, they usually took their main

sleep in the sleeper berth. An additional 6.7 percent

reported that they usually slept in motels. Threequarters of the drivers who used the berth usually

took their sleep in one stretch and most of them

reported spending 8 to 9 hours in the berth. In 

contrast, more than two-thirds of those drivers who

split their rest periods usually spent 4 to 5 hours in

the berth at one time. Further examination of these

data revealed that drivers who split their rests tended

to sleep fewer hours than those who rested in one

stretch. Table 3 presents the amount of time solo and

team drivers typically spend in the sleeper berth. 

Table 2. 

Driver and job characteristics.

Characteristic Total California Georgia Missouri Virginia

Base for Percent 511 129 124 128 130

Owner-Operator 31.5% 23.3% 23.4% 25.0% 53.8%

Union Member 5.3% 4.7% 4.8% 5.5% 6.2%

Irregular Route 84.1% 74.4% 83.9% 88.3% 89.2%

Variable Hours 84.7% 84.5% 83.1% 82.0% 89.2%

Drive Solo 84.1% 82.9% 86.3% 79.7% 87.7%

Table 1. 

Distribution of interviews and refusals by location.

Total California Georgia Missouri Virginia

Interviews 511 129 124 128 130

Refusals 241 7 146 19 69
Researcher

This study was performed by

Decision Research, Santa

Barbara, California; and Essex

Corporation, Goleta, California;

Contract No. DTFH61-89-C-096.

Distribution

This Tech Brief is being distributed according to a standard

distribution. Direct distribution

is being made to the Resource

Centers and Divisions.

Availability

The study final report will be

available from the National

Technical Information Service,

Telephone: (703) 605-6000.

Key Words

truck driver, fatigue, alertness,

commercial motor vehicle 

drivers, shift workers, driver,

countermeasures, work habits,

sleep habits, survey.

Notice

This Tech Brief is disseminated

under the sponsorship of the

Department of Transportation

in the interest of information

exchange. The Tech Brief 

provides a synopsis of the

study’s final publication. The

Tech Brief does not establish

policies or regulations, nor

does it imply FHWA endorsement of the conclusions or 

recommendations. The U.S.

Government assumes no 

liability for its contents or 

their use.

Alertness Maintenance 

Drivers employ a variety of methods and activities for maintaining alertness while 

driving. Some of these include: 

• cooling the truck cab • drinking coffee 

• stretching • eating 

• listening to AM/FM radio • using tobacco products 

• talking on CB • singing 

No single activity stands out as being significantly more effective for maintaining 

alertness than others. However, drivers reported that the most effective group of 

activities included cooling the air by air conditioning or opening windows, stretching 

or changing sitting positions, and listening to the radio or tapes. 

Other options for maintaining alertness while driving include the use of controlled 

substances. Interviewers questioned drivers about the use of such substances by other

drivers known to the respondent. The large majority of drivers interviewed said that

none of the drivers known to them used alertness aids such as speed or cocaine, or

relaxants in the form of marijuana or sleeping pills. Seventy percent of the surveyed

drivers responded that at least some of the drivers they knew used alcohol to relax, 

but nearly a third indicated that none of the drivers known to them use alcohol. 

Most people having conventional jobs arrive at their places of employment not too

long after they awake and begin working in a relatively refreshed state. Because of 

the nature of their employment, however, truckers are often awake for a longer 

period of time, and may already be somewhat fatigued before beginning their job.

Nearly half (44.6 percent) of the drivers reported that they had been awake for 6 or

more hours before beginning their current trip. The elapsed time between waking 

and beginning to drive was most often due to work-related causes, such as waiting 

for a dispatcher to call, or loading and unloading a vehicle. 

Further Research 

These survey results have highlighted the problem of CMV driver fatigue and, in 

particular, have indicated that driver drowsiness episodes are common in long-haul

commercial driving. Since the completion of this study, the FHWA has continued to

implement its comprehensive program of research, technology development, 

rulemaking, education/outreach, and enforcement relating to fatigue and hours of 

service. Numerous specific questions, issues, and opportunities are being addressed. 

In the area of rulemaking, the FHWA is currently in the process of changing the 

60-year-old driver hours-of-service rules; one priority in this rulemaking will be to give

drivers better opportunities for sufficient daily sleep. In research and technology, the

FHWA is performing research on specific operational issues such as sleeper berths,

local/short haul driving, and loading/unloading, as well as supporting research to 

develop technologies that may aid in fatigue management and self management by

drivers. One facet of this work involves in-vehicle systems to continuously assess driver 

alertness based on performance and/or psychophysiological arousal and provide 

feedback to drivers to encourage sufficient rest and sleep.

February 1999

Publication No. FHWA-MCRT-99-006