Transportation Engineering

For more than 35 years, MRI has conducted valuable transportation research for the Federal Highway Administration (FHWA), the National Cooperative Highway Research Program (NCHRP), state highway agencies, and industry and trade associations. We are a leading center for evaluating highway geometric design elements and translating those results into practical geometric design policies. MRI evaluates traffic operations and safety for two-lane and multilane highway improvements and assesses truck operations and safety.

Our research results have contributed to national policies and guidelines, including the AASHTO Policy on Geometric Design for Highways and Streets (commonly known as the Green Book), the Highway Capacity Manual, and the FHWA Manual on Uniform Traffic Control Devices. MRI’s research contributes to safe, practical, and cost-effective solutions to highway design challenges.

Areas of Expertise

• Highway and traffic safety
• Geometric/design safety relationships
• Safety management
• Traffic operations
• Work zone traffic control
• Truck operations and safety
• Pedestrian and bicycle facilities
• Hazardous materials transportation safety
• Highway policies, manuals, and guides

Contact:

Doug Harwood,
Principal Traffic Engineer
(816) 753-7600,
ext. 1571

Highway and Traffic Safety

Highway and traffic safety is the focus of much of MRI's transportation engineering research. MRI is a leading center for using innovative statistical approaches in the analysis of traffic accident data.

Areas of Expertise

• Development of geometric design/safety relationships
• Use of innovative statistical analysis and modeling techniques, including Poisson and negative binomial regression analysis, for evaluating highway safety and highway accident countermeasures
• Conduct of before-after evaluations of highway safety improvement projects
• Development of exposure measures based on traffic volume, mileage, and pavement condition
  (including exposure estimates for wet-pavement and snow-and-ice conditions)
• Conduct of roadway safety audits
• Work zone safety management
• Use of traffic conflict evaluations as a surrogate for accident data

We can evaluate specific highway accident countermeasures and projects including:

• At-grade intersections
• Freeway interchanges, ramps, and speed-change lanes
• Two-lane and multilane highways
• Railroad-highway grade crossings
• Rumble strips
• Pavement marking retroreflectivity and service life
• Pavement skid resistance
• Safety edge treatments to prevent pavement edge dropoffs

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Geometric Design/Safety Relationships

MRI is a leading center for research on relationships between highway geometric design and safety. We have extensive experience in multivariate statistical modeling of such relationships, before-after evaluation of geometric design improvements, and development of practical geometric design policies using research results. Recent MRI research on intersection sight distance and divided highway median widths was incorporated into the AASHTO Green Book. MRI has played an active role in planning and developing FHWA's Interactive Highway Safety Design Model (IHSDM), a series of computer tools to provide an explicit evaluation of the safety performance of proposed designs. MRI has contributed to IHSDM modules for accident prediction, diagnostic review of at-grade intersection designs, geometric design consistency, driver/vehicle performance, and traffic analysis. MRI prepared the AASHTO Guidelines for Geometric Design of Very Low-Volume Local Roads and is currently preparing portions of the forthcoming TRB Highway Safety Manual.

Areas of Expertise

MRI conducts research on the safety of the following geometric design elements:

• Lane and shoulder width
• Horizontal alignment
• Vertical alignment
• Sight distance
• Roadside slopes and clear zones
• Median types and widths
• Passing lanes
• At-grade intersections
• Left- and right-turn treatments
• Interchange ramps and speed-change lanes
• Work zone taper length, median crossover designs, and barrier applications

Research for NCHRP is under way to consider the need for modification of geometric design policies concerning design speed and passing sight distance. Products prepared for clients have included research reports, manuals, guidelines, handbooks, design policies, benefit/cost and cost-effectiveness procedures, and resource allocation procedures.

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Safety Management

MRI is the prime contractor for producing FHWA’s SafetyAnalyst computer software tools. SafetyAnalyst will provide state-of-the-art analytical tools to identify and manage a system-wide program of site-specific, cost-effective improvements to highway safety. SafetyAnalyst tools will include:

• Network screening to identify sites with promise for safety improvement
• Diagnosis of safety concerns at specific sites and selection of appropriate countermeasures
• Economic analysis and priority ranking of proposed countermeasures
• Safety effectiveness evaluation of countermeasures

More detailed information on SafetyAnalyst is available at www.safetyanalyst.org.

MRI also has developed the Resurfacing Safety Resource Allocation Program (RSRAP) presented in NCHRP Report 486, Systemwide Impact of Safety and Traffic Operational Design Decisions for 3R Projects. RSRAP software allows a highway agency to select an optimal program of safety improvements for implementation in conjunction with resurfacing projects. Through NCHRP Project 3-56(2), MRI staff can provide technical support to RSRAP users. More details are available at www.rsrap.org.

MRI has developed guides as part of the NCHRP Report 500 series to assist highway agencies in implementing the AASHTO Strategic Highway Safety Plan. The guides that have been completed or are currently being prepared by MRI address safety improvement for unsignalized intersections, horizontal curves, older drivers, bicycles, motorcycles, emergency medical services, and safety data analysis.

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Traffic Operations

MRI conducts traffic research on two-lane and multilane highways, at-grade intersections, and freeway interchanges. We prepared the two-lane highway chapter of the Highway Capacity Manual and played a key role in producing the Highway Capacity Manual chapter on rural and suburban multilane highways. MRI developed major portions of TWOPAS, the state-of-the-art computer simulation model of two-lane highway operations, and has used the model in evaluating potential improvements to two-lane highways. We also developed the FHWA guide on Low-Cost Methods for Improving Traffic Operations on Two-Lane Highways and have assessed European 2+1 roadway designs.

Areas of Expertise

• Two-lane and multilane highway operations
• At-grade intersection operations
• Freeway interchange operations
• Speed limits and speed enforcement
• Vehicle performance on steep grades
• Passing lanes on two-lane highways
• Turnouts on two-lane highways
• Shoulder use by slower vehicles
• Left- and right-turn lanes
• Two-way left-turn lanes

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Work Zone Traffic Control

MRI staff has evaluated safety and mobility in highway work zones and worker protection in maintenance and construction work zones. Staff also has studied traffic management techniques to accelerate construction and minimize traffic disruption, and MRI staff has conducted training for federal and state agencies and for contractor associations. Research results have been incorporated in Part VI of the FHWA Manual on Uniform Traffic Control Devices and in Chapter 9 of the AASHTO Roadside Design Guide. MRI is participating in the development of an FHWA training course on advanced work zone management and design.

Areas of Expertise

• Traffic control plan development
• Work zone speed limits
• Work zone safety management
• Worker protection
• Internal traffic control plans
• Work zone barriers and attenuators
• Strategies for accelerating construction

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Truck Operations and Safety

MRI performs extensive research on truck operations for highway agencies, industry, and trade groups. As part of FHWA's Comprehensive Truck Size and Weight Study, we evaluated the extent of geometric design improvements needed for selected truck networks to accomodate current and potential larger trucks. In other research for FHWA, MRI evaluated existing geometric design and traffic control policies for trucks. We also have modeled truck performance on upgrades in the TWOPAS computer simulation model. MRI recently prepared NCHRP Report 505, Review of Truck Characteristics as Factors in Roadway Design. MRI prepared a CTBSSP synthesis on highway/heavy vehicle interaction and is currently preparing a CTBSSP synthesis on use of on-board technology to enhance commercial truck and bus safety.

Areas of Expertise

• High- and low-speed offtracking in turns
• Truck rollover threshold
• Model for predicting truck speed profiles on steep upgrades and downgrades
• Performance of single- and double-trailer trucks and longer combination vehicles (LCVs)
• Passenger-car equivalents of trucks for operational evaluations
• Geometric design requirements for trucks
• Hazardous materials transportation safety
• Role of truck tires in safety
• Truck considerations in work zone design
• On-board technology for improving truck and bus safety

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Pedestrian and Bicycle Facilities

MRI performs research to identify effective measures to accommodate pedestrians and bicyclists on public rights-of-way. MRI staff identify ways to balance conflicting needs of pedestrians, bicyclists, and motorists so all modes of travel are accommodated safely and efficiently. Recent legislation requires all transportation agencies to accommodate walking and bicycling in routine planning, design, construction, operations, and maintenance activities. MRI has served as editor for the forthcoming AASHTO Guide for the Planning, Design, and Operation of Pedestrian Facilities and is conducting research on ways to implement the Americans with Disabilities Act and the regulations of the U.S. Access Board.

Areas of Expertise

• Design criteria for pedestrian facilities
• Improved design and traffic control of channelized right-turn roadways for pedestrians and bicyclists
• Design and traffic control for pedestrians who are blind or have vision impairments
• Design criteria for bicycle facilities
• Bicycle-tolerable shoulder rumble strips
• Accommodating bicyclists at trail-highway crossings

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Hazardous Materials Transportation Safety

MRI has extensively reviewed hazardous materials transportation safety for the Federal Highway Administration. We have estimated truck accident rates in evaluating alternative hazardous materials routes and compared the relative risks of long-distance shipping of hazardous wastes by highway and rail. MRI developed a manual and training course on hazardous materials transportation safety for the National Renewable Energy Laboratory.

Areas of Expertise

• Risk assessment and routing analyses
• Analysis of accident and incident data
• Regulatory compliance

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Highway Policies, Manuals, and Guides

MRI has helped highway agencies prepare policies, manuals, and guides related to highway engineering, including:

• Updating and technical editing of the 2001 AASHTO Policy on Geometric Design of Highways, commonly known as the Green Book
  
  
• Developing the AASHTO Guidelines for Geometric Design of Very Low-Volume Local Roads (ADT<400)
  
  
• Revising and technical editing of AASHTO’s forthcoming Guide for Planning, Design, and Operation of Pedestrian Facilities
  
  
• Developing several chapters in the Highway Capacity Manual
  
  
• Preparing chapters on rural two-lane highways and urban and suburban arterials for the forthcoming TRB Highway Safety Manual

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