Research Needs Statement describes a series of studies to examine the safety and
operational performance of women commercial (truck and bus) drivers with the potential
outcome of increasing their numbers with resulting safety and economic
The United States and Canada face a long-term and worsening
shortage of commercial truck and bus drivers, even though U.S. unemployment
hovers at nearly 8% of the labor force.
The chronic and continuing driver shortage has prompted government and
industry officials to look for ways to expand the base of potential commercial
drivers. Significantly expanding the
base of potential drivers would not only lessen labor shortages, it would
improve safety by allowing carriers to be more selective in their hiring. Numerous studies (e.g., Knipling et al.,
2004) have shown that approximately 10-15% of commercial drivers are associated
with 35-50% of crash risk. Increasing the
number of potential drivers would mean that carriers could be more selective in
their hiring. Eliminating a substantial
portion of high-risk driver hires would significantly reduce industry-wide
risk, and would do the same at the level of individual companies.
Women are the biggest untapped demographic group for
commercial motor vehicle (CMV) driving.
Women currently represent only about 5% of U.S. truck drivers per the
Bureau of Labor Statistics. They are 46%
of bus drivers per BLS, though this statistic includes mostly school bus
drivers. Industry sources suggest that 10-15%
of motor coach drivers are women.
Regardless of the overall driving safety of women compared to men,
greatly increasing the number of women drivers would improve CMV safety by
enabling greater selectivity of drivers, as suggested above. Yet there are also indications that female
commercial drivers are generally as safe, and probably safer, than their male
counterparts. To the extent that women
are safer than men, increasing their numbers would improve CMV safety.
Among the general population of motorists, males are
unquestionably riskier than females. As
Shinar (2007, P. 349) stated, “Gender is a great divide among drivers in their
driving style, driving violations, and crash involvement. . . . In general, men
are more likely to exhibit overt aggressive behaviors than women . . .[and]
this difference extends to the world of driving.” A new report from the European Transport
Safety Council (2013) reviews extensive evidence showing that males have far
more crash involvements and serious injuries than do women, although most
statistics showing these differences are not controlled for mileage
exposure. The report also cites various
studies showing male-female differences in risk-taking and other unsafe
attitudes and behaviors. Research
suggests that, compared to females, males drive faster, violate more traffic
rules (including alcohol limits), are more likely to view safety interventions
(e.g., alcohol interlocks, safety belts) negatively, and are more likely to
lose vehicle control.
Evans (2004) looked at male-female traffic citation ratios
within six different age and racial groups.
The male-female risk ratio was 2.0 or higher in all six subgroups. He also cites survey data showing that males
have about twice the propensity to speed, as well as less inclination to
moderate their driving in adverse safety conditions (e.g., slippery
roads). Further, Evans presents
extensive evidence of a strong association between blood testosterone levels
and risk. He plots age curves for male
testosterone, arrests for non-traffic crimes, and involvement in single-vehicle
motor vehicle crashes. These three age curves
are almost identical. Evans also
presents compelling statistics showing that male-female differences in accident
risk begin almost from birth. This
further suggests biological origins.
Regardless of extent to which male-female risk differences are
constitutional as opposed to cultural, it is clear that they are deep-seated
The AAA Safety Foundation conducted an online survey of self-reported
aggressive driving behaviors. Survey sampling
and response weighting were designed to provide nationally representative statistics
on U.S. drivers aged 16 and older. More
than 78% of drivers reported having engaged in at least one aggressive driving behavior
over the past year. The most common such
behaviors were purposely tailgating another vehicle, yelling at another driver,
and honking one’s horn in anger. Males
were significantly more likely than females to have engaged in all eight of the
aggressive behaviors addressed. Gender differences
were most pronounced for the most extreme (but least frequent) behaviors. Males were more than three times as likely to
have exited their vehicles to confront another driver or to have bumped or
rammed another vehicle on purpose.
Women represent approximately 5% of truck drivers, although
this statistic is approximate and does not capture either mileage exposure or
variations in driver gender for different types of trucking operations. Crash statistics provided by the FMCSA for
2006-2009 show that women were 2.0% of the drivers involved in truck
property-damage-only (PDO) crashes and 2.7% of those in fatal crashes. Crash statistics for motorists in general
show lower crash incidence rates per 100,000 drivers for females than for
males, especially for severe crashes. In
2009, the female involvement rate per 100,000 drivers was 26% lower than the
male rate for PDO crashes, but 64% lower for fatal crashes. A low relative involvement in severe crashes
is especially important in CMV transport because it means reduced carrier
exposure to liability from catastrophic crashes.
A specific safety and health advantage for females over
males is a lower incidence of Obstructive Sleep Apnea (OSA) and other
safety-relevant medical conditions.
Among the general population, OSA incidence among females is about half
that of males (Young et al., 1993; Young et al., 2002). Among drivers, the difference might be even
greater. Reed and Cronin (2003) reported
the incidence of self-reported “sleeping difficulties” among female truck
drivers to be only 2%, far less than other reports of sleep disorders among
male drivers (e.g., Pack et al., 2002), although results across different
studies and methodologies might not be comparable. OSA is associated with elevated crash risks
and, increasingly, liability claims against CMV transport companies. Females also have lower rates of
cardiovascular illness than males; driver medical crises like heart attacks are
another safety concern in CMV transport.
On the other hand, given a crash, female truck
drivers appear to be more vulnerable to injury than their male
counterparts. In the four-year period
2005-2008, women were 1.7% of the drivers involved in injury crashes, but 5.2%
of the drivers who were themselves injured.
Biomechanics research has revealed numerous male-female differences
relating to bones, muscles, and joints (Voie, 2012; Guan et al., 2012). Differential morbidity in crashes could also
partially be an artifact of age differences between female and male
drivers. Many female drivers enter the
profession during their 40s and 50s, often after their children are grown (Reed
and Cronin, 2003). Often they enter as
team drivers with their husbands. A
detailed review of the age distributions of drivers killed and injured in
crashes would shed light on this question.
Increased injury vulnerability might also be related to commercial
vehicle safety belt design. Bergoffen et
al. (2005) observed that “belts were not as comfortable or effective with
large- or small-statured individuals.”
Another possible vulnerability of women commercial
drivers is to assault at truck stops, rest areas, or other locations. In one survey (Reed and Cronin, 2003),
one-third of female truck driver respondents claimed to be victims of
harassment several times a week, and many felt so unsafe at truck stops that
they generally did not leave their trucks to exercise or to eat. While the atmosphere for women drivers has
improved over the past decade, personal safety remains a concern.
The above crash and behavioral statistics suggest that greatly increasing
the number of women truck and bus drivers could result in a significant
decrease in serious CMV crashes. The
statistics are only suggestive, however, since no reliable exposure statistics
are available, and since the problem has not been analyzed in depth. Moreover, the prospect of more women truck
and bus drivers raises operational and security issues beyond crash involvement
per se. There are questions about non-driving
personal safety. Driver performance
measures like reliability, comportment, customer relations, retention, and
absenteeism encompass more than safety per
se but are still relevant to long-term safety outcomes.
No published U.S. research has examined the safety performance of women
commercial drivers, the potential safety effects of increasing their numbers,
and implications for motor carriers wishing to expand their pool of potential
drivers to include more female drivers.
An envisioned series of studies (conducted separately or as one
integrated effort) would do this, pursuing the specific research objectives
such as the following:
the crash, traffic violation, and inspection violation experiences of female
commercial drivers and compare it to those of male drivers.
Comprehensively review research literature on the safety of female commercial
drivers, with emphasis on driving safety, but also addressing non-driving work
safety (e.g., loading/unloading, vehicle ingress/egress), and personal safety (i.e.,
statistics and review literature on gender differences in crashes and traffic
violations among non-commercial adult motorists.
ergonomic and other vehicle design issues relating to use of commercial
vehicles by female operators (e.g., operator size and strength requirements,
ability to reach foot pedals and other controls, safety belt design). This could also include non-driving ergonomic
issues; e.g., related to tractor and trailer ingress/egress, vehicle
inspection/maintenance, cargo loading/unloading, and cargo securement.
motor carrier safety directors on the safety performance of women drivers and
related personnel, health, and operational issues. Identify priority problems and successful
in-depth case study interviews with a sample of motor carriers to learn of
their experiences with women drivers and any policies they have developed to
support women drivers in their fleets. Identify effective management practices
relating to women drivers and more broadly related to enlarging the pool of
women commercial drivers to find out their perspectives on these issues and,
specifically, to identify perceived barriers or other difficulties they face. Such surveys could be stratified by age
and/or driving tenure for representativeness and for broader perspectives. Another likely stratification is solo versus
(8) Survey females
in comparable non-driving occupations to determine their views of commercial
driving. This might include former CMV drivers
who have left the industry.
analysis, research, and development (e.g., training, outreach) needs for
fostering an increase in female drivers.
prototype industry outreach literature and/or media to encourage expanded industry
recruiting and hiring of women drivers.
project supports public safety, economic opportunity and equality, industry
performance, and government goals. The
project is justified on economic grounds alone, but it would also bring safety
benefits. The Federal Motor Carrier
Safety Administration’s (FMCSA’s) strategic mission is to “Reduce crashes, injuries, and fatalities involving CMV
transportation through education, innovation, regulation, enforcement,
financial assistance, partnerships, and full accountability. A specific FMCSA priority in its 2012-2016
Strategic Plan is to remove high-risk
commercial drivers from service. This
project would directly support this FMCSA goal by increasing the potential CMV driver labor pool,
thereby enabling carrier selection and hiring of drivers to be more
selective. As suggested above, the worst
15% of (overwhelmingly male) drivers represent up to half of all motor carrier
crash liability risk; replacing these high-risk drivers with qualified female
drivers would likely reduce CMV-at fault crashes substantially.
The entire research
program suggested above could be achieved given 18-24 senior-level person-months
and supporting junior and administrative staff.
The project could also be conducted as a series of smaller, separate
efforts. This might include
university-based masters- and doctoral-level projects. A large-scale industry outreach and/or media program
based on the research (Objective 10 above) would require separate budgeting and
would be more expensive.
Motor carriers, truck and bus industry
groups, insurance companies, FMCSA, NIOSH, academia, other types of
work-related transportation companies and organizations.
This research needs statement has been
reviewed and endorsed by the TRB Committee on Women in Transportation, ABE70.
effectiveness would be measured by increases in the number of female CMV
drivers and their job performance relative to males.
research needs statement was prepared principally by Ellen Voie, CAE, President
& CEO, Women in Trucking; PO Box 400, Plover, WI
54467-0400, (888) 464-9482, Ellen@WomenInTrucking.org,
and Ronald R. Knipling, Ph.D., President, Safety for the Long Haul, Inc., (703) 533-2895,
Women, commercial drivers, truck drivers, motorcoach drivers, gender, truck
safety, driver risk, truck stops, driver shortage.
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