Safety Data Case Studies

2022

Alabama's West South Boulevard Redesign Safety Assessment
This case study summarizes a safety analysis conducted by FHWA's Geometric Design Lab (GDL), in collaboration with the Alabama Department of Transportation and the FHWA Alabama Division. GDL used the Interactive Highway Safety Design Model (IHSDM) software to assess the safety performance of West South Boulevard, a high-volume, high-speed suburban arterial in Montgomery, Alabama. The results of the data-driven analysis informed ALDOT's decision-making on the project and increased confidence in the pedestrian safety elements selected for the final design. W South Boulevard represents a facility type that is common throughout the United States, especially where suburban and rural areas interface and mixed land uses are adjacent to major freeway corridors. This example showcases one way that data-driven safety analysis and crash prediction available through IHSDM can enable agencies to make informed investments in road user safety.

Massachusetts Safety Data Visualization efforts
This case study presents a safety analysis and technology improvement project conducted by the Massachusetts Department of Transportation (MassDOT) to increase access to roadway safety-related data for multi-disciplinary and multi-jurisdictional stakeholders in the State. MassDOT developed a series of tools and analyses to upgrade the State's web-based safety data portal, IMPACT, and provide MassDOT's safety partners across the State with greater access to data, capacity, and insights to encourage traffic safety initiatives and awareness. MassDOT's innovative use of traditional and non-traditional data sources allowed the agency to analyze many of the State's core safety priorities and emphasis areas. The improvements to the IMPACT platform were the result of a collaborative process between MassDOT and the agency's institutional and jurisdictional partners, and it will support and promote safety initiatives throughout Massachusetts.

Minnesota DOT's I-35 Planning Study
This case study describes the Minnesota Department of Transportation's (MnDOT's) use of the Enhanced Interchange Safety Analysis Tool (ISATe) as a part of a planning study for an approximately 7-mile segment of Interstate 35 (I-35) in Carlton County. This study identified safety, operational, and mobility needs along the corridor and developed alternatives which were then coordinated with upcoming infrastructure replacement projects. The I-35 planning study is an example of incorporating quantitative safety analysis as part of a comprehensive review process. MnDOT's work to obtain stakeholder feedback and analyze existing safety conditions allowed the project team to establish safety as a project need. Additional evaluation of specific needs led MnDOT to develop a suite of alternatives that balanced environmental sensitivity with access and safety. ISATe provided the technical capacity to assess the study area's baseline conditions based on existing geometrics and traffic, and estimate predicted crashes based on forecast conditions. The benefit-cost analysis provided further confidence that MnDOT's alternatives will be cost effective and will provide a high level of benefit to users of the I-35 corridor.

Texas DOT's I-37 Interstate Access Justification
This case study presents a safety analysis performed by the Texas Department of Transportation (TxDOT) for an Interstate Access Justification Report. The Interstate 37 (I-37) corridor is an important freight route, critical hurricane evacuation linkage, and the only crossing of the Nueces River within 25 miles. Several planning studies identified the need for mainline widening and the replacement of the Nueces River Bridge. TxDOT reviewed the study area's historic crash frequency and rates to make targeted improvements to the project design. After this review, the TxDOT project team used the Highway Safety Software to predict crashes along I-37 for both a No Build scenario with no changes to the corridor and a Build scenario with proposed capacity, mobility, and safety alternatives. The results indicated that predicted crashes are expected to decrease with implementation of the proposed improvements compared to the existing conditions for both the base and design years.

2021

Michigan’s US 31 at I-94 Interchange Alternatives Analysis
This case study presents MDOT’s iterative approach to project development that used the Interactive Highway Safety Design Model (IHSDM) software to identify a preferred design alternative based on a broad suite of traffic, safety, and cost considerations. The strategic application of IHSDM allowed MDOT to assess different design alternatives and project assumptions to make data-driven decisions for the proposed I-94 and US 31 interchange and surrounding network.

WIS 75 Intersection Screening & Project Development Process
This case study presents a safety analysis conducted by the Wisconsin Department of Transportation (WisDOT) at the intersection of State Highway 75 (WIS 75) and Plank Road (County Road A) in Racine County, WI. WisDOT proactively identified key safety needs early in the project development process and used a data-driven approach to evaluate the safety effects of potential alternatives.

Western Federal Lands Highway Division: Yale-Kilgore Road Safety and Traffic Assessment
This case study presents a safety analysis by the Federal Highway Administration, Western Federal Lands Highway Division (WFLHD) Highway Safety Team. The WFLHD used the Interactive Highway Safety Design Model (IHSDM) software as part of the design process for the rehabilitation of Yale-Kilgore Road.

Acadiana Planning Commission: Data Governance - Louisiana’s Local Government Partnerships
The Acadiana Planning Commission (APC) is the metropolitan planning organization (MPO) covering the Lafayette, Louisiana urbanized area. Although Lafayette proper is highly urban, the MPO in total covers a seven-parish area in southern Louisiana that also includes low density rural communities.

Data Management & Spatial Integration: Missouri's Transportation Management
This case study documents how the Missouri Department of Transportation's (MoDOT's) Transportation Planning Division (TPD) coordinates with the Information Systems unit (the agency's information technology unit), and the State's Traffic Records Coordinating Committee (TRCC) to form a leadership group that supports the State's data management and integration activities. The State's Transportation Management System (TMS) stores all transportation-related data maintained by the agency.

Kentucky Transportation Cabinet – Kentucky's Network Screening Process
The purpose of this case study is to describe Kentucky's network screening methodology for all State-owned roads, as well as local roads classified as a collector street or above. The Kentucky Transportation Cabinet's (KYTC) Highway Safety Improvement Program requires a data-driven process to identify sites with a potential safety need and prioritize projects.

Indiana Department of Transportation – Indiana's State Road 37 Improvement Project
This case study presents an interchange alternatives analysis from the Indiana Department of Transportation (INDOT). The analysis supported a multi-agency planning and engineering effort that involved INDOT, the Indianapolis Metropolitan Planning Organization, Hamilton County, Town of Fishers, and City of Noblesville.

South Carolina Department of Transportation – South Carolina's SC 61 Rural Road Safety Project
The purpose of this case study is to present an example application of the American Association of State Highway and Transportation Officials (AASHTO) Highway Safety Manual (HSM) to support a rural road corridor analysis.

2020

New York Department of Transportation Data Integration in CLEAR New York State's Safety Management Tool
This case study presents NYSDOT's significant advancement in safety data integration and analysis. NYSDOT is developing a State-specific safety management system known as the Crash Location and Engineering Analysis Repository (CLEAR).

Ohio Department of Transportation Data Governance Ohio's People, Processes, and Technology
By incorporating people, processes, and technology into its approach, Ohio's DOT continues to successfully implement data governance as part of its overall institutional strategy

2017

Delaware Valley Regional Planning Commission's Innovative Traffic Data Sharing Practices
This case study highlights how the Delaware Valley Regional Planning Commission (DVRPC) promotes traffic data sharing with other agencies and makes traffic and geographic information system data available to the public.

Virginia Department of Transportation Innovative Procedures in Traffic Volume Estimation
This case study presents how the Virginia Department of Transportation (VDOT) estimates traffic volumes on secondary local roadways using a trip generation method instead of taking short-duration counts in the field.

New York State Department of Transportation: Engagement of Local Agencies in Traffic Volume Collection and Random Sampling Procedures
This case study highlights two noteworthy practices at the New York State Department of Transportation regarding traffic data collection agreements with local agencies and random sampling procedures to select short-duration traffic count locations

Southeast Michigan Council of Governments: Innovative Traffic Data Quality Assurance/Quality Control Procedures and Automating AADT Estimation
This case study highlights two noteworthy practices at the Southeast Michigan Council of Governments regarding short-duration traffic count validation procedures and an automated annual average daily traffic estimation process.

Asset Management in Oregon Case Study
The Oregon Department of Transportation (ODOT) is responsible for managing and maintaining its roadway assets. Managed assets include barriers, traffic signals, lighting, pavement markings, and signs. ODOT has developed an innovative inventory of its assets and evaluates asset condition in order to efficiently manage maintenance efforts.

2016

Washington State and Tribal Data Sharing Partnership
The Washington State Department of Transportation successfully partners with tribes to share data and tools helping to improve safety at the local level.

Pennsylvania's State-Specific SPFs and CMFs
Pennsylvania Department of Transportation (PennDOT) used Part C of the Highway Safety Manual (HSM) to develop State-specific safety performance functions (SPFs). PennDOT believes that pre-selecting applicable CMFS, and developing State-specific and regionally calibrated SPFs offers the best approach for addressing the State's unique features and for dealing with the inherent differences among areas within the State.

South Carolina Safety Data Improvements Through Electronic Crash System Deployment
The South Carolina Department of Transportation (SCDOT) and the South Carolina Department of Public Safety (SCDPS) implemented the South Carolina Collision and Ticket Tracking System (SCCATTS), a long-term initiative to improve law enforcement data quality. SCCATTS supports decision making with quality data and efficient data sharing among stakeholders

Maryland's Data Linkage and Analysis to Support Decision making
The University of Maryland's National Study Center for Trauma and Emergency Medical Services (NSC) receives data from several State agencies and provides integrated data analysis using the Crash Outcome Data Evaluation System (CODES) methodology.

Alabama's Safety Planning Tools for MPOs Roadway Safety Data and Analysis
The Alabama Department of Transportation (ALDOT) led the effort to develop ALSAFE, a spreadsheet-based safety tool that can be used for short- and long-range transportation safety planning. ALDOT developed ALSAFE to serve as a safety planning tool for Metropolitan Planning Organizations (MPOs).

Systemic Safety Analysis in Illinois
The Illinois Department of Transportation (IDOT) published the AASHTO Highway Safety Manual Illinois User Guide with Illinois Calibration Factor and Default Values in 2014. Also in 2014, IDOT published the Systemic Safety Improvements: Analysis, Guidelines and Procedures Guidebook.

Roadway Safety Data Governance in Illinois
The Illinois Department of Transportation (IDOT) has implemented an enterprise data governance approach for managing data collection, storage, distribution, and use throughout the organization. The Illinois Traffic Records Coordinating Committee (ITRCC) works to advance IDOT safety analysis activities, which includes identifying severe crash locations and segments, prioritizing locations for treatment, and performing systemic safety analyses.

North Carolina's State-Specific CMFs
North Carolina is one of a small number of States that have actively pursued developing their own crash modification factor (CMF) "short list" for countermeasures that are deployed throughout the State. The North Carolina Department of Transportation (NCDOT) wanted to develop a list of CMFs to use in benefit cost analyses across the State.

Arizona Importing Local and Tribal Data For Safety Analysis
The Arizona DOT is importing Local and Tribal data for safety. A joint pilot project with FHWA encouraged ADOT to create a new process allowing business users to import the data from local agencies, export combined State and local/tribal data, and load data into AASHTOWare Safety Analyst™ for analysis.

Utah's and Kentucky's Innovative Use of GIS-Based Tools
The objective of this case study is to illustrate Kentucky and Utah DOTs effective use of usRAP and UPlan, respectively. Both programs include data collection, and analysis methods that facilitate highway safety improvements.

Tennessee's Horizontal Curve Database
In 2012, the Tennessee Department of Transportation (TDOT) accomplished its initial data collection for its entire roadway network, which includes all interstates, state highways, arterials, collectors, and local roads. With these data, TDOT created a horizontal curve database with approximately 40,000 miles of roadways with curves.

Delaware Valley Regional Planning Commission (DVRPC) Integrating Safety into the Planning Process at the MPO Level
The Delaware Valley Regional Planning Commission has been using GIS in planning and programming for project selection. The tri-state area of South New Jersey, Delaware, and Pennsylvania have promoted the shared resources as a way of keeping safety as a priority in the planning process.

Colorado's Implementation of Level of Service of Safety
The objective of this case study is to illustrate how Colorado uses GIS to spatially integrate roadway data with crash data, develop SPFs, visualize data, and implement the Level of Service of Safety (LOSS) method to assess a roadway's safety performance.

Iowa's Real-Time Data Integration of Snowplow Information and Roadway Safety
Iowa has been in the forefront of using GIS finding new and innovative ways to improve safety. The case study highlights a GIS-based tracking system tied to the snow removal operation.

2015

New Hampshire's Intersection Inventory
New Hampshire is one of the states successfully using Safety Analyst. The case study highlights their efforts to also develop an intersection inventory to enhance the data available for analysis.

Michigan Department of Transportation Safety Data Processes and Governance Practices
The purpose of this case study is to summarize how the MDOT incorporates a data governance structure into their standard business operations and how it has helped them to improve their safety data systems and processes.

New Hampshire Department of Transportation Safety Data Systems and Processes
The purpose of this case study is to highlight noteworthy practices of the New Hampshire Department of Transportation in leveraging technology to enhance safety data management.

Utah Department of Transportation Safety Data Processes and Governance Practices
The purpose of this case study is to highlight innovative data management strategies at Utah Department of Transportation (UDOT) that support the use of technology to benefit safety programs.

Developing and Using State Specific Safety Performance Functions (SPFS) In Virginia Roadway Safety and Analysis
The Virginia Department of Transportation (VDOT) emphasizes data-driven decision-making and demonstrates leadership to improve safety and safety data. As a result, VDOT developed and implemented a comprehensive set of State-specific Safety Performance Functions (SPFs) covering 98 percent of its State-maintained roadway locations.

2014

Michigan Roadsoft – Integration of State and Local Safety Data Case Study
The program provides roadway asset management, field data collection, maintenance management, and safety analysis tools to local agencies. Each local agency maintains its own data in a local copy of Roadsoft and shares that information with the State upon request.

Ohio Location Based Response System – Integration of State and Local Safety Data Case Study
The program provides consistent location referencing for all public roadways. ODOT maintains the statewide roadway inventory database and integrates data owned and supplied by the local agencies.

Roadway Safety Data and Analysis Case Study: Safety Analysis in Project Development in Louisiana
The purpose of this case study is to describe the success experienced by the Louisiana Department of Transportation and Development (LADOTD) using safety data and safety analysis techniques in a broad range of project development practices in maintenance, design exceptions, environmental reviews, work zone construction and operations, and local roadway owner coordination.

Wisconsin Information System for Local Roads – Integration of State and Local Safety Data Case Study
This program results in an all-public-roads database using a single LRS and basemap. Local agencies collect and own the data, but the centralized system is available to all authorized users.

Development of Safety Performance Functions for Network Screening in Illinois
In 2006, the Illinois Center for Transportation, Illinois Department of Transportation (IDOT) and the University of Illinois at Urbana-Champaign performed a research project to develop state-specific SPFs to use in the State's network screening process.

Using Predictive Methods for Alternative Selection in Florida
With the publication of the HSM, Florida Department of Transportation (FDOT) initiated a pilot project to investigate the differences in project cost based on FDOT Plans Preparation Manual standards compared to Green Book standards to use as a tool for decision making and alternative selection during the project development process, with specific emphasis on the evaluation of safety costs utilizing the HSM predictive method.

Using Predictive Methods for a Corridor Study in Idaho
The Idaho Transportation Department (ITD) contracted with a consultant to conduct a comprehensive review of existing Idaho State Highway 8 (Idaho 8) corridor conditions. The review identified deficiencies related to traffic operations, roadway geometry and cross section, access control, and safety with an overall purpose to identify and prioritize operational improvements over a 10-year period. FHWA's IHSDM was used to evaluate existing traffic, roadway geometry, and predict crashes using these and the corridor's recent crash history.