FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION

FMCSA Contact: Robert Carroll, MC-RTR, (202) 366-9109

Impact of Local/Short-Haul

Operations on Driver Fatigue: 

Field Study

Introduction

In local/short-haul (L/SH) operations, commercial motor vehicle drivers primarily make trips

of 100 miles or less from their home bases. L/SH activity includes local “pickup and delivery

(P&D)” as well as other kinds of operations. Though researchers have examined the effects

of driver fatigue and other safety issues in long-haul operations, they know little about how

those issues affect L/SH operations—the largest segment of the trucking industry. Localservice trucks account for 58% of large truck registrations, 28% of miles traveled, and 38%

of fatal crash involvements. 

The Federal Motor Carrier Safety Administration (FMCSA) conducted a two-phased research

project on the safety issues in L/SH operations and the extent to which fatigue is an issue in

the industry. Researchers convened focus group sessions in Phase I, then conducted a field

study in Phase II to determine objectively if fatigue is a safety issue in L/SH trucking. 

The Phase I report, Impact of Local/Short Haul Operations on Driver Fatigue: Focus Group

Summary and Analysis, was published in August 1998. This Tech Brief summarizes the Phase

II report, Impact of Local/Short Haul Operations on Driver Fatigue: Final Report, published 

in August 2000. 

Background 

Long-Haul v. L/SH Operations

Whereas long-haul drivers may be on the road for several days or weeks, driving and 

sleeping at irregular times, L/SH drivers typically work during daylight hours and return to

their homes after a daily shift. Long-haul drivers generally do not perform tasks other than

driving, but L/SH drivers may make multiple deliveries during a single trip, load and unload

a vehicle, lift and carry packages, interact with customers, and perform other tasks during a

daily work routine. Because fatigue is a critical safety issue for long-haul drivers, researchers

sought to identify to what extent fatigue and other safety issues affect L/SH operations. 

Phase I: Focus Groups 

In Phase I of the study, researchers held 11 focus group sessions in 5 states. Eighty-two L/SH

drivers participated in the sessions—discussing general safety issues within the industry as

well as fatigue-related factors. Drivers identified the following critical safety issues, ranked

in order of importance (1 = most important):

1. problems caused by drivers of light vehicles (e.g., cars and pickup trucks), 

2. stress due to time pressure,

3. inattention, 

4. problems caused by roadway/dock design, and 

5. fatigue. 

Tech Brief

The goal of the Federal Motor

Carrier Safety Administration

(FMCSA) is to reduce the 

number and severity of large

truck-involved crashes

through more commercial

motor vehicle and operator

inspections and compliance

reviews, stronger enforcement

measures against violators,

expedited completion of 

rulemaking proceedings, 

scientifically sound research,

and effective CDL testing,

recordkeeping, and sanctions.

The Office of Research and

Technology manages research

and technology development

and deployment programs 

for the FMCSA.

FMCSA R&T activities 

encompass a range of issues

and disciplines relating to

motor carrier safety, including

problem assessment; policy,

safety management, and outreach; drivers; truck and bus

vehicle safety performance;

and compliance, enforcement

and operations.

Driver alertness and fatigue

primarily supports current 

and future hours-of-service

rulemaking activities, along

with fatigue outreach and

fatigue management 

technology development.

Office of Research and Technology

400 Seventh Street, SW

MC-RT, Room 3107

Washington, DC 20590
Following are the top fatigue-related issues identified by

L/SH drivers, ranked in order of importance (1 = most

important):

1. not enough sleep, 

2. hard/physical workday, 

3. heat/no air conditioning, 

4. waiting to unload, and 

5. irregular meal times. 

In the focus groups, drivers identified fatigue as an issue

in the L/SH industry—though they thought it was less

critical for them than for long-haul truckers. Participants

pointed out that they work during daylight hours, have

work breaks that interrupt driving, end their shifts at

home, and sleep in their own beds at night. For L/SH 

drivers fatigue apparently results from a normal day’s

work and is impacted by their personal lives (e.g.,

whether they get enough sleep at night)—similar to the

fatigue experienced by day-shift workers in non-driving

professions. 

Purpose

The primary purpose of Phase II of the research was to

conduct a field study to determine objectively if fatigue

is a safety issue in L/SH trucking. The results of the focus

group effort in Phase I served as the foundation for the

field study in Phase II. 

Methodology

Phase II consisted of an on-road study in which L/SH

trucks were instrumented with data collection equipment and driven by L/SH drivers on typical workdays.

Researchers collected both quantitative and qualitative

data to identify safety issues and determine the extent

to which fatigue is an issue in the L/SH industry. Multiple

components of fatigue were considered, including those

determined through:

• subjective measures, such as self-reported level of

stress;

• objective measures, such as the degree of eyelid 

closure—a reliable measure of driver fatigue; and 

• physiological measures, such as indications of sleep

quantity and quality as collected by wrist activity 

monitors.

Two L/SH companies participated in the study—one that

hauls beverages and another that hauls snack foods.

Both companies were paid for their participation. Four

types of L/SH trucks were used in the study: a 15-foot

panel van, an 18-foot panel van, a box truck, and a 

class B straight truck (generally a single vehicle with a

gross vehicle weight rating of more than 26,000 pounds).

These trucks represent typical in-service trucks used by

each company. 

Researchers installed unobtrusive, compact, and reliable

“black box” data collection systems in the trucks. Several

small video cameras monitored each truck driver and

surrounding traffic situation, and sensors collected data

from the vehicle’s instruments. (See Figure 1.) Performance data were collected as 42 drivers worked their 

typical delivery routes for approximately 2 weeks. The

average age of the participants was 31. All drivers took

part in the study voluntarily and were paid in addition 

to their regular compensation.

The data collection equipment was designed to capture

driver performance associated with “critical incidents,”

i.e., near-crash events. The data used in the analysis were

gathered from three sources: 

• truck instrumentation (e.g., equipment measurements

of forward velocity, lateral acceleration, and braking

sensors, or an analyst’s review of composite-image

video tapes of the driver and driving environment); 

• demographic forms and pre- and post-shift 

questionnaires completed by drivers; and 

• wrist activity monitors, which measure the quantity

and quality of drivers’ sleep. 

Findings

Collectively, participating drivers spent about 28 percent

of each workday driving, 35 percent loading and 

unloading, 26 percent performing other tasks (e.g., 

merchandising and vehicle inspection), 7 percent waiting

to unload, and the remainder of the day eating, resting,

or doing other activities. 

Figure 1. 

Five Video Camera Angles and Approximate

Fields of View in L/SH Field Study
Researchers identified 249 critical incidents (i.e., 

near-crash events), including: 

• 137 critical incidents attributed to “other” drivers, 

i.e., not L/SH drivers; 

• 77 critical incidents attributed to L/SH drivers;

• 20 critical incidents in which the L/SH driver was

involved only as an observer; and 

• 15 critical incidents in which the L/SH driver responded

to another type of situation, such as an animal in the

road. (See Figure 2.)

L/SH Driver At-Fault Critical Incidents

L/SH drivers were at fault in 77 of the 249 critical 

incidents. Researchers reviewed the videotapes and 

narratives of events and attributed one or more 

potential causes to each of those critical incidents. For

example, if a L/SH driver ran a red light, a researcher

might identify both inattention and stress due to time

pressure as potential causes of the critical incident.

Following is a list of the potential causes researchers

most often attributed to L/SH driver at-fault critical 

incidents:

• inattention (57 critical incidents),

• fatigue (28 critical incidents),

• stress due to time pressure (25 critical incidents),

• driver education/protocol (10 critical incidents),

• roadway/dock design (8 critical incidents), and 

• overconfidence (7 critical incidents). (See Figure 3.)

The majority of L/SH driver-at-fault critical incidents were

caused by very few drivers. Two drivers accounted for 

26 percent of the 77 critical incidents attributed to L/SH 

drivers, and 8 drivers accounted for 60 percent of those

incidents. Thirty-three percent of the L/SH drivers had no

at-fault critical incidents.

L/SH Driver Fatigue

Researchers found evidence of driver fatigue and 

inattention, to a statistically significant degree, during

the interval preceding L/SH driver-at-fault critical 

incidents. In 21 percent of the 77 critical incidents in

which L/SH drivers were at fault, researchers identified

fatigue as a contributing factor. In L/SH driver-at-fault

critical incidents, the drivers’ PERCLOS values (a validated

indicator of driver drowsiness based on slow eyelid 

closure) were significantly higher than in other types of

critical incidents. The drivers’ OBSERV values (a validated

indicator of driver drowsiness based on an observer 

rating of drowsiness, as determined by facial expression)

also were significantly higher than in other types of 

critical incidents. 

L/SH drivers tended to be involved in fatigue-related 

critical incidents earlier in the workweek: no fatiguerelated critical incidents occurred after the fourth day of

a driver’s workweek. This data may suggest that drivers

get less sleep during their “weekend” breaks than 

during the workweek. 

The wrist activity monitor data suggested that L/SH 

drivers who showed signs of fatigue and were involved

in at-fault critical incidents had less sleep and poorer

quality of sleep than drivers who did not show outward

signs of fatigue. The findings agree with the common

sense notion that quantity and quality of sleep influence

the level of fatigue experienced the next day.

Researchers suggested that the off-duty behavior of the

drivers was the primary contributing factor in the level

of fatigue demonstrated during the workday. Those L/SH

drivers who demonstrated fatigue on-the-job likely

would have experienced fatigue at any job within or

outside of the trucking industry. 

Younger/Inexperienced Drivers

The study showed that younger/inexperienced L/SH 

drivers were significantly more likely to be involved in

critical incidents than were older/more experienced 

drivers. In addition, younger/inexperienced drivers 

exhibited higher on-the-job drowsiness, as indicated by

Figure 3. 

Potential Causes of L/SH Driver-At-Fault 

Critical Incidents

Figure 2. 

Critical Incidents in L/SH Field Study
Researcher

Center for Transportation

Research

Virginia Polytechnic Institute 

and State University

1700 Kraft Drive, Suite 2000

Blacksburg, VA 24061

Contract No. DTFH61-96-C-00105

Distribution

This Tech Brief is distributed

according to a standard distribution. Direct distribution is made to

the Service Centers and Divisions.

Availability

The study final report is available

from the National Technical

Information Service, No. PB2001-

101416INZ.

Key Words

alertness, driving, fatigue, field

study, inattention, instrumented

vehicles, local/short-haul, truck

Notice

This Tech Brief is disseminated

under the sponsorship of the U.S.

Department of Transportation

(USDOT) in the interest of 

information exchange. The Tech

Brief provides a synopsis of the

study’s final publication; it does

not establish policies or regulations, nor does it imply USDOT

endorsement of the conclusions 

or recommendations. The U.S.

Government assumes no liability

for its contents or their use.

Web Site

All FMCSA Tech and Analysis

Briefs are available at:

http://www.fmcsa.dot.gov. 

Please send us your comments

and suggestions about the Tech

and Analysis Briefs. 

Technical Writer

Wendy Grzywacz, Avalon

Integrated Services.

their PERCLOS and OBSERV measurements. Researchers hypothesized that younger/

inexperienced truck drivers may be overrepresented in crashes, like their counterpart

younger/inexperienced passenger vehicle drivers. 

Lane Change and Backing

In 15 percent of the lane-change critical incidents, researchers identified drowsiness as a 

contributing factor, compared to 7 percent for non-critical-incident lane changes. During

lane-change maneuvers, fatigued drivers spent more time looking straight ahead than 

drivers who were not fatigued. In backing maneuvers, fatigued L/SH drivers spent more time

looking in the right-forward direction. These findings may suggest that fatigued drivers

spend less time scanning their environment and tend to fixate on relatively unimportant 

sections of their field of view. 

Recommendations 

Based on the results of the study, researchers made the following recommendations.

Drowsiness/Inattention: L/SH companies should encourage drivers to monitor their levels of

drowsiness and inattention and institute policies that allow drivers to take breaks for short

naps without reprimand.

Sleep Hygiene: L/SH companies should encourage drivers to come to work well rested and

train drivers on the hazards of operating heavy equipment when tired.

Driver Training: L/SH companies and federal and state governments should improve the

training of younger/inexperienced drivers and consider requiring all L/SH drivers to have 

special licenses to operate L/SH trucks (similar to the class B licences required for drivers of

articulated trucks).

Driver Screening: L/SH companies should improve driver selection and screening to identify

unsafe drivers before they are hired. 

Public Monitoring of Driver Performance: L/SH companies should consider implementing initiatives similar to the “How’s my driving?” program, which provides a phone number on the

back of long-haul trucks to solicit feedback from the general public on drivers’ performance. 

Further Research 

The FMCSA currently is conducting research in the related areas of car-truck interaction and

on-board systems to monitor driver fatigue and inattention. Researchers also recommended

future efforts in the following areas: cellular phone use by L/SH drivers, the impact of driver

age on L/SH driving performance, and methods to identify unsafe drivers.

References

Hanowski, R., Wierwille, W., Gellatly, A., Early, N., and Dingus, T. Impact of Local/Short Haul

Operations on Driver Fatigue: Final Report, FMCSA, FMCSA No. DOT-MC-00-203, NTIS No.

PB2001-101416INZ, Washington, D.C., Sept. 2000. 

Hanowski, R., Wierwille, W., Gellatly, A., Early, N., and Dingus, T. Impact of Local/Short Haul

Operations on Driver Fatigue: Focus Groups Summary and Analysis, Federal Highway

Administration, Office of Motor Carriers, FHWA No. FHWA-MC-98-029, NTIS No. PB99-

105785INZ, Washington, D.C., Aug. 1998.

Impact of Local/Short Haul Operations on Driver Fatigue: Focus Group Summary and Analysis

(Tech Brief), Federal Highway Administration, Office of Motor Carriers, FHWA No. FHWAMCRT-98-002, Washington, D.C., Nov. 1998. May 2001

Publication No. FMCSA-MCRT-01-006