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Truck & Bus Safety Research Needs


Truck & Bus Safety Research Needs Transportation Research Board (TRB) Truck & Bus Safety Research Committee (ACS60) Revised March 2, 2021

This document identifies truck and bus safety research and development needs in 11 different topical areas. Like other TRB committees, the Truck & Bus Safety Research Committee (ACS60) seeks to identify and articulate research needs in its discipline and to encourage research organizations to perform needed research. To this end, the committee has identified research needs in its major topic areas. For many, the committee has written more detailed Research Needs Statements (RNSs) on the TRB RNS website (http://rns.trb.org/).

ACS60 asks both research-funding and research-performing organizations to consider these research needs in their strategic planning and allocation of resources. ACS60 members are available to provide further explanations regarding them. ACS60 also welcomes research needs statements written by non-members. More information is available on our website [http://www.ugpti.org/trb/truckandbus/] or by contacting committee chair Bob Scopatz (bscopatz@vhb.com) or committee research coordinator Nicholas Kehoe (nicholas.kehoe@toxcel.com).

Research Needs in Eleven Focus Areas The following research needs are organized into 11 focus areas, corresponding to topics within the committee’s scope and its subcommittees. Those research needs prefixed with a “RNS” are further articulated online as Research Needs Statements; the others may be written and uploaded as RNSs in the future. Readers interested in those topics should review those RNSs since they contain extensive information. Although the needs below are classified by principal category, almost all of them relate to other categories as well.

Problem Assessment & Data:

RNS: Toward Naturalistic Driving Crash Representativeness. Develop crash and event profiling, stratification, and data weighting schemes to make naturalistic driving safety-critical event (SCE) datasets conform more closely to crash datasets such as the LTCCS, thus increasing their validity and usefulness.

RNS: Multi-Dimensional, Omnibus Crash Problem Size Analysis to Support Countermeasure Assessments. Generate en masse a huge number (>10,000) of specific, countermeasure-relevant crash problem size statistics on different crash types, causes, other factors, vehicle types, etc. to support countermeasure assessments.

RNS: Single-Vehicle Crash Involvement as a Commercial Driver Risk Indicator. Assess the validity, safety benefit, and practicality of using involvements in CMV single-vehicle crashes as indicators of driver risk.

RNS: Survey Methodologies for Motor Carrier Research. Review the fundamentals of survey research methodologies in the context of CMV transport. Generate guidelines for improving CMV transport surveys.

RNS: CMV Crash Risk by Time-of-Day. Review the available data sources to determine large truck crash rates and risks by time-of-day. This includes numerator (crash number, harm) and denominator (exposure) measures.

RNS: Exposure Data to Support Improved Truck Crash Risk Estimates. Evaluate existing and potential exposure measures corresponding to crash variables for generating more valid and meaningful relative risk estimates. Publish a compendium of exposure (“denominator”) variables and data similar to existing crash (“numerator”) reports.

RNS: Analyze Injury Outcomes of Rural and Urban Truck Crashes. Review characteristics and factors contributing to crash severity in rural and urban areas. Generate strategies for prevention.

Trip- and Carrier-Specific Exposure Risk Estimation. Develop an algorithm whereby the exposure risk of any trip and, in the aggregate, any larger operation could be estimated based on multiple known risk factors such as trip length, types of roads traveled, traffic densities, time-of-day, and day-of-week.

Methods for Representative CMV Driver Sampling. There are wide variations in CMV driver operations types, vehicles driven, traffic environment, physical job requirements, and other characteristics. The envisioned study would delineate key CMV driver characteristics for the development of representative samples.

Light Vehicle and CMV Following Distances. Monitor highway vehicle-to-vehicle following distances, by vehicle type combinations (both light vehicle types and truck types), to gain insights into light vehicle-CMV rear-end crashes.

Suicide by Truck. A European study reports that 65 of 379 fatal truck crashes (17%) are suspected suicides by car drivers. Assess this problem in North America and determine implications for crash reporting, carrier safety management, and countermeasures.


State Practices Relating to Exempt Motor Carrier Operations. Examine state laws, regulations, and practices relating to MC operations that are exempted from HOS and other regulations; e.g., which industries/commodities, actual exemptions, safety data comparing exempt to regulated carriers/industries.

Effects of New Hours-of-Service Rules. Assess effects of the 2013 HOS rule changes using large, nationally representative samples; this includes effects on CMV safety (driving and non-driving), driver health, driver income, the driver shortage, and the overall safety and economic performance of the industry.

Enforcement & Compliance:

RNS: Optimized CMV Enforcement Field Test. Conduct a large-scale regional field test to determine the optimal mix of MCSAP-supported enforcement strategies, and likely involving a shift toward relatively more traffic enforcement.

RNS: Understanding What Violations Report on the CDLIS. Examine state and other jurisdictional practices (e.g., reporting criteria) and performance (e.g., completeness, accuracy) in reporting traffic convictions to other states and to the Commercial Drivers License Information System (CDLIS).

RNS: Traffic Violation-Triggered Carrier Audits. Assess the merits of initiating carrier audits following extreme traffic violations such as overspeeding, based in part on the Australian experience using this approach.

Characterize Non-MCSAP Traffic Enforcement. Quantify and characterize CMV traffic enforcement activity (stops, violations, convictions) by non-Motor Carrier Safety Assistance Program (MCSAP) police officers, and determine its significance as a supplement to MCSAP-funded traffic enforcement. Note: Also see “Optimized CMV Enforcement Field Test” RNS below.

Driver Health & Wellness:

RNS: Why Are Commercial Drivers So Unhealthy? Determine the relative roles of different job factors, and also non-job factors including demographics, personal traits (resulting in self-selection for the job), and health-related attitudes.

RNS: Work-Related Distress & Mental Disorders in Commercial Drivers. Determine the prevalence, health effects, and safety effects of work-related distress and mental disorders among CMV drivers.

RNS: Commercial Driver Health and Wellness Programs to Impact Driving Safety. Test two hypotheses: (1) CMV drivers who adopt a health and wellness lifestyle will be safer drivers; (2) Employee H&W programs (e.g., screenings) will promote driver behavioral changes and additional carrier wellness initiatives.

Sleep Disorder Screening Criteria. Determine efficacy and cost effectiveness of implementing new sleep disorder screening criteria for CDL certification in driver medical examinations. FMCSA is contemplating new criteria (e.g., BMI) for requiring driver sleep lab testing. Examine the costs and benefits of such changes in terms of health, driving safety, and operational practicalities.

Nutrition, Diet, Weight Management for CMV Drivers. Elucidate driver eating habits as part of health and weight management factors for their implications in overall driver wellness and fitness. Study driver’s nutritional knowledge, accessibility of healthy food especially during over-the-road operations, and the willingness of drivers to engage in healthy eating.

Large & Small Carrier H&W Program Assessment. Conduct case studies of programs geared toward drivers in both large and small carriers to identify viable H&W interventions, return-on-investment, and best practices that can improve human capital strategies to viably serve both employer communities.

CMV Driver Physical, Medical, Fitness Standards Linked to Functional Abilities. Conduct research to elucidate medical and H&W selection, placement, and retention standards linked to transient states, diseases and medical conditions, and to specific functional abilities to drive and to crash causation.

CMV Driver Injuries from Slips, Trips, and Falls. Conduct research that identifies the causes and solutions of CMV driver injuries due to lifting and vehicle egress and ingress.

CMV Driver Distress. Determine the prevalence, health effects, and safety effects of work-related distress and mental disorders among CMV drivers. In addition, determine best approaches for providing CMV drivers with health services. Note: See RNS on same topic, listed below.

Assess Truck Stop Rest & Hygiene Services. Assess and compare the driver rest, sleep, and hygiene-related facilities and services available at North American truck stops, including any obstacles drivers face (e.g., cost, availability) in using them.

Health & Safety Communication Strategies with Commercial Drivers. Determine the best media and formats for contacting and communicating with commercial drivers.

Driver Human Factors:

RNS: Self-Assessment Bias among Commercial Drivers. Survey drivers regarding self-assessments of their safety and health, and relate these self-assessments to other driver characteristics, including risk perception, openness to improvement, and objectively measured safety and health.

RNS: Truck Driver Cabin Ergonomics. Assess truck cab ergonomic configurations for the purpose of improving driver comfort and safety. Goals include reduced back pain, reduced fatigue, reduced distraction, and increased safety belt use.

RNS: Investigating School Bus Driver Distraction. Collect naturalistic data on school bus drivers performing their normal driving tasks on bus routes to determine distraction sources.

Strategic Review of Crash Causes & Countermeasures. Conduct a comprehensive, top-down review of truck and bus safety efforts (Federal, State, industry, public education, etc.) as related to our knowledge of crash causation and characteristics. Identify under-targeted causes and under-supported countermeasures.

Dimensions of Personal Risk. Validate and elucidate personal risk dimensions, and design safety programs based on this understanding. Dimensions may include performance vs. behavior and temporary states vs. enduring traits.

Multi-Component Model of Fatigue’s Role in CMV Crashes. Driver fatigue’s most obvious crash causal role is seen when asleep-at-the-wheel is the Critical Reason (proximal cause). The envisioned study would define, verify, and quantify other crash causal mechanisms and scenarios traceable to fatigue.

Isolate the Fatigue and Other Driving Effects of Time Awake. Time awake is well-established as an independent physiological factor in alertness. Yet, in almost any CMV driver schedule, driving/work hours co-vary with time awake to a high degree. The envisioned research would differentiate the two types of temporal effects and their implications for fatigue management.

Evaluate Driving Simulators as a Testbed for CMV HOS Studies. Driving simulators offer numerous advantages over real driving as research testbeds; i.e., subject safety, scenario and test event standardization, repeatability, and sophisticated measurement. A research question, however, is whether subjects can sustain long, HOS-relevant hours driving a simulator.

Carrier Safety Management:

RNS: Women Commercial Drivers & Safety. Examine the safety and operational performance of women commercial drivers with the potential outcome of increasing their numbers.

RNS: Improved Safety Management for Prime Contractor & Subcontract Carriers. Analyze and document safety challenges which might exist in large transport operations making extensive use of subcontract carriers and drivers. Identify and articulate effective safety management practices for such organizations, both from the perspective of “parent” companies and their small subcontractors.

RNS: Carrier Based Validation of Driver Selection Tools. Conduct carrier-based validation studies of various tests and measurements used for driver selection and other assessments to improve driver selection.

Validation of Driver Analytic Modeling. As part of the above project or separately, validate analytic modeling of driver safety and retention to prevent spurious inferences due to Type I errors (false positives generated randomly by multiple post hoc comparisons), regression to the mean, and similar pitfalls.

Improving Carrier Risk Management Practices. Identify means for motor carriers to identify and understand their crash risks and available countermeasures in areas beyond regulatory compliance.

Crash Investigation and Analysis for Carriers. Identify and delineate effective carrier practices to investigate and analyze their crashes, considering carriers’ multiple needs to learn from their mistakes, reduce future risks, avoid undue liability and adverse publicity, and treat crash-involved drivers fairly.

Media for Communications with Small Carriers and Drivers. Determine the best media and formats for messages regarding safety information, including new regulations, enforcement, best practices, and time-critical (e.g., traffic, weather, safety recalls) information.

Ecodriving Pilot Tests and Program Development in North America. Ecodriving is a primarily European initiative that promotes fuel economy and lower-risk driving. There is a need for demonstration pilot tests and other activities to develop and promote the concept in North American fleets.


International Review of CMV Driver Training and Knowledge/Skill Requirements. Review regulatory requirements and industry best practices in various developed nations (e.g., Canada, Mexico, Europe) to identify possible models for improved training of commercial drivers in the U.S.

CMV Driver Advanced Competency Training & Certification. Identify training and performance criteria for “Master Driver” certification, either by governments, carriers, or independent standards organizations. Create recognized and standardized higher levels of driver competency beyond the CDL.

Cargo Securement Training Needs Assessment and Training Development. Analyze driver training needs associated with cargo securement for various trailer and operations types, based on both regulations and “beyond compliance” best practices. Design and develop needed training.

Analyze CMV Driver Trainer Competencies. Analyze competencies essential for success as a CMV driver trainer. This would include generic training competencies as well as those specific to CMV driving.

Pre-Driver Training Candidate Screening Tool. Develop and validate a self-test questionnaire to screen potential CMV drivers prior to basic training, thereby reducing “wash outs.” The instrument would likely address vocational interests, personality, values, and behavioral history (e.g., past crashes/disqualifiers).

Alternative Compliance:

Alternative Compliance Pilot Test. Pilot test carrier safety management strategies which improve upon, or in some cases supplant certain traditional Commercial Vehicle Operations safety management regulatory and compliance practices. Develop, evaluate and promote new safety strategies, including technology applications, for appropriate carriers using discrete incentives or inducements, such as tax credits or exemptions relating to FMCSA's Compliance, Safety, Accountability (CSA) system. The evaluation would involve both federal and state agencies and would determine the effectiveness of alternative compliance concepts, and the potential for expanding such concepts as a means to expand the reach and coverage of enforcement efforts throughout the nation. It would consider audit, documentation, or certification schemes to verify and document best practices and safety outcomes. It would support FMCSA’s planned Beyond Compliance initiate to recognize non-mandatory carrier safety initiatives.

Vehicle Design & Technology:

RNS: Technical Characteristics of Paratransit Buses Currently Built In The U.S. Develop a database with technical information on the construction, fueling, safety, passenger securement and durability of current paratransit buses built in the U.S.

RNS: Indirect Visibility Systems (IVSs) on Buses. Conduct literature review and focus groups to identify potential indirect visibility system configurations for certain bus types to improve visibility, increase driver situation awareness, and reduce crashes.

Pilot Test of Truck Platooning. Conduct a pilot test to determine the safety and fuel efficiency benefits of truck platooning employing vehicle-to-vehicle communications and synchronized braking and acceleration.

Assess Foundation Brake Performance Monitoring Systems. Examine and test existing monitoring systems for foundation brakes (particularly drum brakes), such as systems that can detect failures and/or excessive wear and alert the driver through electronic systems.

Safety Impacts of Aged Retroreflective Sheeting. In 1999 FMCSA 571.108 established that trailers must be fitted with retroreflective sheeting or specifically marked. Minimum standards were established for white and red sections of sheeting. Now, more than 20 years later, many of the trailers still have the same sheeting. Unlike signs where aging is the only significant threat to recognition, trucks are frequently at angles relative to other traffic, thus further reducing the effectiveness of retroreflective materials. Research is needed to understand drivers’ needs and the potential for improvements to driver training and current standards. This research could study the influence of retroreflective sheeting on driver recognition as well as the effect of sheeting age and light conditions on driver recognition.

Safety Impacts of Slow and Stopped Trucks. Vehicles in limp mode and truck-trailers stopped in traffic continue to be struck in the rear daily. When a vehicle strikes the rear of a trailer, many of these high-speed crashes lead to severe injury and death. According to the Fatal Analysis Reporting System, the most common fatal rear-ended event involves a vehicle traveling 40 to 70 mph and striking at stopped or very slow vehicle. A large percent of these crashes involve trucks. This research would study factors associated with driver responses to slow or stopped trucks, investigate improvements to vehicle design to highlight slow or stopped trucks, and provide recommendations to reduce the number of rear-end crashes involving slow or stopped trucks.

Roadway Design & Operations:

Safety Effects of Differential Speed Limits. Resolve the long-debated question of whether differential highway speed limits for trucks and light vehicles contributes to safety, or degrades it.

Motorcoach Safety:

Safety Ramifications of Small Motorcoaches. Assess occupant protection and other safety concerns regarding the use of smaller capacity motorcoaches.

Safety Evaluations of Dedicated CMV Lanes. Pilot test bus and truck dedicated lane and traffic light prioritization schemes with potential safety benefits for CMVs and motor vehicles in general.


Address a wide variety of truck and bus safety research needs in 11 topic areas.

Sponsoring Committee:ACS60, Truck and Bus Safety
RNS Developer:This document was compiled by Ronald R. Knipling, Safety for the Long Haul Inc., rknipling@verizon.net and Nicholas Kehoe, Toxcel, LLC (Nicholas.Kehoe@toxcel.com). Numerous committee members have contributed topical ideas and written RNSs.
Date Posted:04/03/2014
Date Modified:03/02/2021
Index Terms:Trucks, Buses, Highway safety, Crashes, Countermeasures, Human factors, Traffic violations, Commercial drivers,
Cosponsoring Committees: 
Data and Information Technology
Safety and Human Factors
Education and Training
Vehicles and Equipment

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