Preliminary Investigations

The Caltrans Division of Research, Innovation and System Information (DRISI) receives and evaluates numerous research problem statements for funding every year. DRISI wishes to conduct Preliminary Investigations on these problem statements in order to better understand the need for the research in light of efforts already made on the topic nationally and internationally.

By Program Steering Committee

Design/Construction

• PI-0317 - Scope of Work Development Procedures for A&E Multiphase Service Contracts (PDF) (TXT) - March 2022
  
• PI-0319 - Evaluation of the Use of Silt Fence as Check Dams (PDF) - March 2022
• PI-0278 - Traffic Modeling of Potential Emergency Wildfire Evacuation Routes (PDF) - May 2021
• PI-0241 - Safe and Sustainable Temporary Construction Barriers (PDF) - April 2021
• PI-0279 - Geometric Design Strategies for Speed Reduction and Traffic Calming: Survey of Practice (PDF) - March 2021
• PI-0230 - Passive Flood Barrier: Survey of Practice (PDF) - December 2020
• PI-0291 - Left Turn Pocket Approach Taper Design Guidance (PDF) - October 2020
• PI-0235 - Roadside Design Strategies for Fire Presuppression: Survey of Practice (PDF) - June 2020
• PI-0236 - Post-Fire Roadside Design Strategies: Survey of Practice (PDF) - June 2020
• PI-0238 - Early Warning Overheight Vehicle Detection Systems for Falsework in Work Zones: Survey of Practice (PDF) - November 2019
• PI-0223 - Plastic Culverts in Fire-Prone Areas: Survey of State Practice (PDF) - July 2019
• PI-0050 - State of the Practice of Highway Roadside Stormwater Management Using Green Infrastructure (PDF) - December 2018
• PI-0051 - Increasing the Recycling of Materials Used for Highway Construction (PDF) - December 2018
• PI-0025 - Construction Materials Management Systems: Survey of State Practice (PDF) - August 2018
• Bicycle Safety Improvement Programs: Survey of Practice (PDF) - December 2017
• Trees on Non-Recoverable and Non-Transversable Slopes: Survey of State Practice (PDF) - July 2017
• Online Systems to Process Time-and-Materials Billings: Survey of State Practice (PDF) - June 2017
• Project Delivery Document Management Systems (PDF) - October 2016
• Analyzing Incident and Accident Data to Improve Worker Safety (PDF) - August 2016
• Managing Parking Congestion at the H. Dana Bowers Safety Roadside Rest Area (PDF) - Jun 2016
• Identification of Standards for Acceptability of In­Place Temporary Concrete Barriers (PDF) - March 2016
• Green Infrastructure Strategies: Tools and Practices to Measure the Sustainability of Transportation Projects (PDF) - December 2015
• Closing Additional Traffic Lanes Adjacent to Work Areas: A Survey of State Practices and Related Resources (PDF) - November 2015
• Quantitative Cost-Benefit Analyses of the Use of Automated Machine Guidance in Construction: An Examination of Current Practice (PDF)  - September 2015
• Safety and Stability of Stormwater Infiltration BMPs Adjacent to Roadsides (PDF) - August 2015
• Application of Quantitative Risk Management Practices to Project Development: A Survey of State Practice and Related Research (PDF) - July 2015
• Identifying Best Practices for Evaluation of Design Innovations (PDF) - June 2015
• The Role of Landscape Architects in State Departments of Transportation: A Survey of State Practice (PDF) - May 2015
• Comprehensive Design Guidance for Cycle Tracks (PDF) - March 2015
• Advanced Modeling Techniques for Enhanced Constructability Review, Phase II: A Survey of State Practice and Related Research (PDF) - July 2014
• Low-Profile Barrier Design Alternatives (PDF) - June 2013
• Effects of Outdoor Advertising Displays on Driver Safety (PDF) - October 2012
• Advanced Modeling Techniques for Enhanced Constructability Review: A Survey of State Practice and Related Research (PDF) - March 2012
• Validating the Outcome of Partnering on Major Capital Projects (PDF) - March 2012
• Comparing In-House Staff and Consultant Costs for Highway Design and Construction: Follow-Up Investigation (PDF) - October 2011
• Effective Application of Traffic Calming Techniques (PDF) - September 2011
• Comparing In-House Staff and Consultant Costs for Highway Design and Construction (PDF) - July 2011
• Roadside Management Strategies to Reduce Greenhouse Gases (PDF) - June 2010
• Trees and Highway Safety (PDF) - March 2010
• Green Technologies for Reducing Slope Erosion (PDF) - January 2010

District

• PI-0246 - Analyzing the Potential of Geofencing for Electric Bicycles and Scooters in the Public Right of Way (PDF) - January 2020
• PI-0138 - Sloped-Down End Barriers Used in Diverging Diamond Interchange Designs: Survey of State Practice (PDF) - April 2019
• PI-0170 - Travel Forecasting Guidance: Survey of Practice (PDF)  - February 2019
• Coordinated Transportation Services for Seniors and People with Disabilities (PDF) - November 2017
• Bar-Built Estuary Modeling (PDF) - December 2014
• Traffic Counts Literature Website Search (PDF) - November 2014
• Automated Video Incident Detection Systems (PDF) - October 2012
• Environmental Effects of Cured-in-Place Pipe Repairs (PDF) - June 2012
• Traffic Noise Generated by Rumble Strips (PDF) - March 2012
• Curb Radius and Injury Severity at Intersections (PDF) - February 2012

Division Of Research, Innovation And System Information

• PI-0339 - Literature Search Human Trafficking Research During Major Sporting Events and Related to Transportation Facilities Literature Search (PDF) - March 2024 (PDF) - February 2024
• PI-0290 - Transportation-Related Equity Indicators to Improve Mobility and Transportation System Access for Low-Income and Disadvantaged Communities (PDF) - January 2021
• PI-0268 - Measuring the Benefits of Transportation Research: Survey of Practice (PDF) - July 2020
• PI-0243 - Implementing and Reporting on Efficiencies and Process Improvements (PDF) - December 2019
• PI-0226 - Transportation-Housing Linkages (PDF) - September 2019
• PI-0233 - Cost Estimating Improvement Initiative: Tool Usage Survey (PDF) - October 2019
• PI-0088 - Workspace Planning and Design: Survey of State Practice (PDF) - January 2019
• PI-0013 - Safety and Health Program Administration (PDF) - May 2018
• PI-0014 - Environmental Impacts of Connected and Automated Vehicles (PDF) - February 2018
• Cost Estimating Improvement Initiative: Literature Review (PDF) - June 2017
• Cost Estimating Improvement Initiative: Survey of Caltrans Districts by Functional Unit (PDF) - June 2017
• Quantifying Passenger Rail Access Mode Shift (PDF) - April 2016
• Impact of Active Transportation on Reducing or Avoiding Vehicle Miles Traveled and Greenhouse Gas Emissions (PDF) - January 2016
• Engineering Workforce Development in Transportation Agencies: A Survey of State Practice (PDF) - November 30, 2015
• Fostering Innovation within State Departments of Transportation (PDF) - July 2015
• Geospatial Highway Inventory and Traffic Safety Applications: A Survey of State Practice and Software Solutions (PDF) - January 2014
• Alternative Transportation Financing Strategies (PDF) - January 2013
• Highway Worker Safety: Automated Speed Enforcement (PDF) - August 2012
• Highway Worker Safety: Technologies (PDF) - July 2012
• Highway Worker Safety: Policies, Practices and Legal Issues (PDF) - July 2012
• Highway Worker Safety: Education and Outreach (PDF) - July 2012
• Highway Worker Safety: State Move Over Laws (PDF) - July 2011
• Application of Cross-Asset Optimization in Transportation Asset Management: A Survey of State Practice and Related Research (PDF) - June 2012
• Implementing Research Results: Highlighting State and National Practices (PDF) - March 2011
• Intellectual Property: National and International Perspectives (PDF) - June 2009

Environmental

• PI-0260 - Historic Aquatic Conveyance Systems: Survey of Practice (PDF) - July 2020
• PI-0248 - Measuring the Effectiveness of a Stormwater Public Education Campaign: Survey of Practice (PDF) - December 2019
• PI-0240 - Use of Vegetation to Control Trash in Freeway Right of Way (PDF) - October 2019
• PI-0074 - Assessing Permanent Shading Impacts on Riparian Plant and Aquatic Species and Habitat (PDF) - February 2019
• PI-0180 - Underwater LED Light Guidance Devices (PDF) - February 2019
• PI-0046 - Assessing the Impacts of LED Lighting to Wildlife (PDF) - January 2019
• PI-0042 - Effects of Roadside Barriers on Near-Road Air Pollutant Dispersion and Concentration (PDF) - June 2018
• PI-0038 - Soil Amendment Guidance for Infiltration and Stormwater Treatment (PDF) - October 2017
• Brake Wear Emissions in Particulate Matter (PDF) - October 2017
• Fish Passage Programs: Survey of Practice (PDF) - September 2017
• California Tiger Salamander Landscape Genetics (PDF) - December 2016
• Tide Gates: Technical and Ecological Considerations (PDF) - March 2016
• Determining the Appropriate Amount of Time to Isolate Portland Cement Concrete from Receiving Waters (PDF) - February 2016
• Environmental DNA Detection as a Survey Tool for the Endangered Tidewater Goby (PDF) - January 2015
• One-Way Gates in Wildlife Fencing to Reduce Wildlife-Vehicle Collisions for Small- and Medium-Sized Animals (PDF) - October 2014
• Improved Exclusion Barriers for Desert Tortoises (PDF) - May 2014
• California Amphibian and Reptile Crossing Preliminary Investigation (PDF) - July 2013
• Highway Crossings for Herptiles (Reptiles and Amphibians) (PDF) - November 2012
• Comparing Life Cycle Costs of Fish- and Wildlife-Friendly Culverts with Conventional Culvert Designs (PDF) - January 2012
• Cool Pavements Research and Technology (PDF) - September 2011
• Outreach Efforts Related to Mitigating Impacts on Cultural Resources: A Survey of State Practice (PDF) - January 2011

Equipment

• PI-0303 - Commercial Availability of Electric-Powered Loaders (PDF) - January 2022
• PI-0297 - Teleoperated, Connected, and Automated Vehicles and Equipment for Maintenance Operations (PDF) - March 2021
• Current Availability and Feasibility of Mobile, Fast Fill Hydrogen Refueling Stations (PDF) - August 2019
• Brine Application Equipment and Methodology (PDF) - January 2019
• Natural Frequencies of Pickups and Medium and Heavy Trucks for Use in Component Design (PDF) - June 2018
• Best Practices to Reduce Illness and Injury Rate in Heavy Duty Mechanics (PDF) - February 2015
• Equipment Management Follow-Up (PDF) - February 2013
• Fleet Equipment Asset Management Performance Measures (PDF) - December 2013
• Use of GPS for Equipment and Fleet Management by State DOTs (PDF) - December 2011
• Equipment Management Decentralization by the North Carolina Department of Transportation (PDF) - December 2011
• National Survey of Equipment Management Practices (PDF) - June 2011

Executive

• PI-0312 - Small Disadvantaged Business Enterprise (SB/DBE) Issues in Caltrans Contract and Bid Process - September 2022
• PI-0316 - Use of Data Analytics Teams in the Public and Private Sectors (PDF) - March 2022
• PI-0306 - Activities That May Impact the Diversity of the Caltrans Workforce (PDF) - January 2022
• PI-0302 - Evaluating New Tools for Long-Lasting Efficiencies (PDF) - December 2021
• PI-0298 - Best Practices for Project Delivery Performance Measures (PDF) - September 2021
• PI-0301 - Impacts of Freeway Sitting on Communities of Color (PDF) - August 2021
• PI-0261 - Life Cycle Planning for Intelligent Transportation System Assets: Survey of Practice (PDF) - June 2021
• PI-0292 - Defining Methodologies and Data Sources for Project-Level Performance Measurement (PDF) - April 2021
• PI-0285 - Data Literacy Training Assessment (PDF) - January 2021
• PI-0287 - Measuring the Benefits of Transportation Research (PDF) - December 2020
• PI-0244 - Quantifying the Benefits of Routine and Preventive Maintenance: Survey of Practice (PDF) - April 2020
• PI-0234 - Statewide Asset Data Collection and Management: Survey of Practice (PDF) - March 2020
• Meeting Notes on California Safety Data Business Planning, Data Governance and Management - Southern California Peer Exchange (PDF) - May 2018
• Comprehensive Corridor Planning for Congested Corridors: Survey of Practice (PDF) - January 2018
• Implementing Efficiencies as Part of an Investment Strategy (PDF) - December 2017

Geotechnical/Structures

• PI-0274 - Bridge Deterioration Models and Rates (PDF) - September 2020
• PI-0052 - Use of Web-Based Systems to Manage Contractor Submittals: Survey of State Practice (PDF) - January 2019
• PI-0022 - Application of Carbon Capture and Sequestration Technologies in Transportation Infrastructure Construction Materials (PDF) - June 2018
• Joint Training and Certification of Materials Testers (PDF) - May 2015
• Post-Tensioned Box Girder Deck Replacement Methodology (PDF) - April 2015
• Development of a Validated Methodology for Seismic Analysis and Design of Standard and Pile-Supported Retaining Walls (PDF) - March 2015
• The Use of Unmanned Aerial Systems for Steep Terrain Investigations (PDF) - August, 2014
• Compliance Crash Testing of Side Mounted Bridge Rail (PDF) - March 2013
• Steel Girder End Panel Shear Resistance (PDF) - October 2010
• Geophysical Methods for Determining the Geotechnical Engineering Properties of Earth Materials (PDF) - March 2010
• Improved LRFD/LRFR Specifications for Permit and Fatigue Load Trucks (PDF) - December 2009

Maintenance

• PI-0336 - Multimodal Common Operating Picture for Emergency Services (PDF) - September 2023
• PI-0282 - Use of Recycled Plastic in Asphalt and Concrete Pavement Applications (PDF) - December 2020
• PI-0284 - Surface Applications of Fire Retardants (PDF) - November 2020
• PI-0275 - Alternatives to Flares for Use in Managing Traffic During Moving Lane Closures (PDF) - July 2020
• PI-0231 - Maintenance Practices for Bridge Drains and Expansion Joints: Survey of Practice (PDF) - October 2019
• PI-0245 - DOT’s Use of Alternative Herbicides (PDF) - April 2019
• PI-0009 - California Winter (Non-Snow and Ice) Level of Service Strategies (PDF) - February 2018
• Use of Cold-Applied Adhesive for Raised Pavement Marker Applications (PDF) - October 2017
• Use of Adjuvants for Roadside Vegetation Control (PDF) - July 2017
• Review of Prefabricated Wash Rack Systems (PDF) - June 2017
• Flood Flow Estimation using Large Scale Particle Image Velocimetry (PDF) - February 2017
• Using Remote Control Mowers for Roadside Vegetation Control (PDF) - December 2016
• Equipment for Improving Pavement Crack Cleaning Operations (PDF) - September 2016
• Performance-Based Budgeting for Maintenance Activities (PDF) - June 2016
• Commercial Pavement Marking Management Systems (PDF) - May 2016
• Work Zone Intrusion Alarms for Highway Workers (PDF) - April 2016
• Using Mechanical Ice Breakers to Improve Snow and Ice Removal Operations (PDF) - February 2016
• Mobile Applications for Reporting Maintenance Issues (PDF) - February 2016
• Replacing Intelligent Transportation System Field Elements: A Survey of State Practice (PDF) - November 2015
• Resiliency Metrics for Transportation Planning (PDF) - October 2015
• State Practices on Barrier Use in Wide Freeway Medians (PDF) - July 2015
• Variances in Advance Warning Signs (PDF) - April 2015
• Avalanche Mapping Study (PDF) - April 2015
• Early Warning of Fire Emergencies: Tools and Resources (PDF) - November 2014
• Design Practices and Products for Deterring Copper Wire Thefts (PDF) - May 2013
• Flood Warning Alert Systems (PDF) - December 2012
• Laws to Prevent Metal Theft and Recycling of Stolen Metals (PDF) - November 2011
• Using Life Cycle Cost Analysis in Highway Project Development (PDF) - November 2011
• Measuring and Improving Performance in Incident Management (PDF) - March 2010

Modal

• PI-0334 - Determine Major Gaps in Research on Wildfires and Transportation (PDF) - March 2024
  PI-0321 - Delta Ferries Funding Options and Operational Models (PDF) - March 2022
• PI-0249 - Innovative Technology to Improve Transit Services for Disabled Travelers (PDF) - June 2020
• PI-0277 - Airport Closure in the State of California (PDF) - March 2020
• PI-0224 - California Airport Land Use Planning Handbook Update: Survey of Practice (PDF) - October 2019
• PI-0115 - Integration of Positive Train Control With Earthquake Early Warning Alert (PDF) - January 2019
• PI-0047 - California Aviation System Plan Update: Survey of State Practice (PDF) - October 2018
• PI-0012 - Quantifying the Results of Key Transit Investments (PDF) - March 2018
• Mobility Management Technology (PDF) - May 2016
• Methodologies to Convert Other Modes of Travel to Vehicle Miles Traveled (PDF) - July 2015
• State Aeronautics Roles in Developing Emergency Air Operations Branches (PDF) - September 2014
• Demand Responsive Travel Operation Based on Dynamic Passenger Information (Dynamic Ride Share by Smartphone request) (PDF) - April 2014
• Integrating Transit Data into State Highway Planning (PDF) - July 2012
• Assessing Park-and-Ride Impacts (PDF) - June 2010
• Disaster Recovery Plan (PDF) - December 2009

Pavement

• Concrete Recycling: Reuse of Returned Plastic Concrete and Crushed Concrete as Aggregate (PDF) - September 2012
• Environmentally Friendly Elimination of Moss from Open-Graded Asphalt Pavement (PDF) - April 2011
• Practices and Guidelines for Temporary Transverse Hot Mix Asphalt (HMA) Tapers (PDF) - May 2010

Planning/Policy/Programming

• PI-0327 - Single Package Delivery Fees (PDF) (TXT) - July 2023
  

• PI-0313 - Economic Competitiveness of Warehousing (PDF) (TXT) - March 2022

• PI-0318 - Caltrans Renaming and Removal of Harmful Names and Monuments on Right of Way (PDF) - September 2022
• PI-0293 - Micro-Rail Exploration Study (PDF) - March 2021
• PI-0288 - Effects of COVID-19-Related Telework Policies on the Transportation System (PDF) - January 2021
• PI-0276 - Agricultural Goods Movement System Assessment (PDF) - October 2020
• PI-0237 - Federal Trade Policy Impacts to California's Freight System (PDF) - March 2020
• PI-0100 - Influences on Mode Shift Associated With Various Classes of Bikeways (PDF) - January 2019
• PI-0044 - Data Collection of Bicycle Collisions Occurring on Nonpubli Roadways (PDF) - November 2018
• PI-0024 - Feasibility of Allowing the Use of Twin 33-Foot Trailers in California (PDF) - April 2018
• PI-0015 - Best Practices for Tribal Participation in Transportation Planning and Programming (PDF) - April 2018
• PI-0045 - Pricing and Parking Management to Reduce Vehicle Miles Traveled (PDF) - March 2018
• New Shared Mobility: Literature Search on Current Travel Demand Models and Data Reporting (PDF) - March 2016
• Automated Freight Systems: Current and Future Freight Container Mobility Systems for CA (PDF) - October 2015
• Implementing Strategic Plans: A Survey of State Practice and Related Research (PDF) - July 2015
• Mitigating Freight Impacts on Nearby Communities (PDF) - June 2015
• The Feasibility of Moving Freight on High-Speed Rail Networks (PDF) - April 2015
• Effectiveness of Efforts to Reduce Greenhouse Gas Emissions by Improving Transportation System Efficiency and Pavement Conditions (PDF) - October 2014
• Correlating Transit and Parallel Corridor Congestion: Interviews to Ascertain Current Practice (PDF) - October 2013
• Sustainability Tools and Practices: An Examination of Selected State Departments of Transportation, California Metropolitan Planning Organizations and National Tools (PDF) - March 2013
• Smart Mobility (PDF) - November 2012
• Smart Mobility: A Survey of Current Practice and Related Research (PDF) - April 2012
• Transportation-Related Use of Health Impact Assessments and Similar Tools (PDF) - August 2011
• Rail Preservation Programs: A Survey of National Guidance and State Practice (PDF) - June 2011
• Quantifying the Effectiveness of Air Quality Mitigation Measures (PDF) - April 2011
• Developing Project Initiation Documents: A Survey of State Practice (PDF) - December 2010
• Best Practices for Rural Smart Growth (PDF) - July 2010
• Real-Time Data to Improve En Route Decision Making and Reduce Transportation Demand (PDF) - July 2009
• Designing Highway Facilities To Encourage Walking, Biking and Transit (PDF) - March 2009

Right Of Way and Land Surveys

• PI-0324 - Automated LiDAR Extraction (PDF) (TXT) - October 2021
  
• PI-0324 - Automated LiDAR Extraction Software (PDF) - October 2021
• PI-0049 - Quantifying Right of Way–Related Risks Using Cost Estimating and Risk Management Tools: Survey of State Practice (PDF) - February 15, 2019
• State Department of Transportation National Spatial Data Infrastructure (NSDI) Implementation (PDF) - August 2018
• GIS Standards and Technology Implementation (PDF) - August 2017
• Right of Way Information Management Systems (PDF) - August 2016
• Effective Methods to Protect Underground Utilities (PDF) - December 2015
• Statewide Real-Time Global Positioning System or Global Navigation Satellite System Network Implementation (PDF) - February 2015
• Implementing a Digital Archive Backup and Operational System for Aerial Photography Collections (PDF) - May 2010

Rural

• PI-0257 - Differential Speed Limit on Rural Multilane Highways: Survey of Practice (PDF) - August 2020
• PI-0256 - Differential Truck Speed Limit on Rural Two-Lane Highways: Survey of Practice (PDF) - March 2020
• PI-0023 - Cellular Network Reliability During a Crisis in Rural Areas (PDF) - January 2018
• Utility-Scale Solar Power Generation Facilities in California (PDF) - December 2017
• In-Vehicle Safety Warnings (PDF) - October 2017
• Ensuring Accuracy of Roadway Surface Condition Sensors (PDF) - June 2016
• Use of Vehicle-Mounted Heat Detection Systems to Reduce Animal-Vehicle Collisions (PDF) - May 2016
• Improving Highway Advisory Radio Predictability and Performance (PDF) - August 2011
• Improved Chain Control Operations (PDF) - January 2010

Transportation Safety And Mobility (TS&M)

• PI-0310 - Promising New, Innovative Non-Standard Traffic Signs, Pavement Markings and Traffic Signals (PDF) - March 2022
• PI-0289 - Automated Video Traffic Monitoring and Analysis (PDF) - August 2021
• PI-0296 - Work Zone Safety: Synthesis of Literature and Industry Survey (PDF) - July 2021
• PI-0281 - Transportation Management Plans for Projects Requiring Full Roadway Closure: Survey of Practice (PDF) - November 2020
• PI-0255 - High-Tension Cable Barrier as Guardrail: Survey of Practice (PDF) - July 2020
• PI-0239 - Design of Concrete Barrier as Right- or Left-Side Guardrail: Survey of State Practice (PDF) - December 2019
• PI-0195 - Traffic Incident Management (TIM) Data Collection (PDF) - September 2019
• PI-0148 - Use of Collision Diagramming Systems: Survey of State Practice (PDF) - May 2019
• Crash Test of Type 1 and Type 15 FBS Standards for Ramp Meter Use (PDF) - December 2018
• Improving Motorcycle Safety by Enhancing Roadway Design (PDF) - October 2017
• High-Occupancy Vehicle (HOV) Lane Performance During Non-recurrent Congestion and Alternative Operation Schemes for HOV Lanes: Occupancy Changes, Double HOV Lanes and Clean Air Vehicle Eligibility (PDF) - August 2017
• Impact of Roadside Graphic Displays on Drivers (PDF) - September 2016
• Green Stripe Pavement Markings Adjacent to Edgeline (PDF) - August 2016
• Use of Warranties and Retroreflectivity Values in Pavement Marking (PDF) - April 2016
• Optimum Amount of Money/Resources for Public Outreach During a Major Planned Closure (PDF) - November 2015
• Wrong-Way Driving Prevention Methods (PDF) - October 2015
• Roadway and Roadside Visual Image and Attribute Data Collection and Distribution (PDF) - March 2015
• Wrong-Way Driving Prevention Methods - In-house Preliminary Investigation (PDF) - January 2015
• Overhead Sign Sheeting and Illumination: A Survey of State Practice and Related Research (PDF) - October 2014
• Administrative and Legislative Arrangements of Tolling Agencies (PDF) - June 2014
• Freeway Exit Gore Signage: A Survey of State Practice and Related Research (PDF) - December 2013
• Highway Lighting Practices and Policies (PDF) - October 2013
• 24-Hour Traffic-Responsive Ramp Metering (PDF) - May 2013
• Impacts of Increasing Vehicle-Occupancy Requirements on HOV/HOT Lanes (PDF) - March 2013
• Managed Lanes Case Studies (PDF) - March 2013
• Life Cycle Analysis of Galvanized Metal Guardrail Elements (PDF) - October 2012
• Ramp Metering Design (PDF) - February 2012
• Bicycle-in-Lane Sign Use and Comprehension (PDF) - October 2011
• Safety Implications of the Use of the Flashing Yellow Arrow for Permissive Left Turns (PDF) - January 2011
• Improving Driver Decisions and Performance in High-Speed, Multilane, Complex Conditions (PDF) - December 2009
• Informing a Pedestrian Safety Improvement Program (PDF) - December 2009
• Equal Severity Curve (ESC) Update (PDF) - July 2009
• Crash Reduction Factor (CRF) Update (PDF) - January 2009