SafetyAnalyst software was developed as a cooperative effort between FHWA and participating state and local agencies. The software will be transitioned to become a licensed AASHTOWare product for Fiscal Year 2010.
SafetyAnalyst provides a set of software tools for use by state and local highway agencies for highway safety management. These tools can be used to develop programming for site-specific highway safety improvements following the process and procedures in the Highway Safety Manual (HSM).
SafetyAnalyst incorporates the HSM safety management approaches into computerized analytical tools for guiding the decision-making process. Because it has a strong basis in cost-effectiveness analysis, SafetyAnalyst can play an important role in prioritizing improvements so that highway agencies get the greatest possible safety benefit from each dollar spent in the name of safety.
SafetyAnalyst integrates all parts of the highway safety management process into a single software package. SafetyAnalyst has four analytical tools:
- The Network Screening Tool identifies sites with potential for safety improvements. Measures of effectiveness and statistical methodologies are used to provide a more a reliable list of locations warranting further investigation
- The Diagnosis and Countermeasure Selection Tool is used to diagnose the nature of safety problems at specific sites and assist users in selecting effective countermeasures to address those problems. It facilitates thorough diagnosis through basic collision diagramming and identification of significant accident patterns, and systematic countermeasure selection through site-specific diagnostic questions.
- The Economic Appraisal and Priority Ranking Tool performs an economic appraisal of countermeasures or alternative countermeasures for a specific site, an optimization of sites and countermeasures, and a priority ranking of alternative improvements. Optional benefit methodologies are provided to support requirements of the federal Highway Safety ImprovementProgram
- The Countermeasure Evaluation Tool provides the capability to conduct before/after evaluations of implemented safety improvements. New statistical methods provide valuable feedback on the effectiveness of completed countermeasures for reporting and future planning.
The SafetyAnalyst software tools require a linked database of roadway characteristics, traffic volume, and crash data at the site level. Many of the required data elements are readily available to highway agencies. However, some effort to assemble and format the data will be needed. SafetyAnalyst includes a data management tool to help users import and manage their data. While many additional data elements are desirable and may be evaluated, the minimum set of data elements required to use SafetyAnalyst are crash and traffic data and either roadway segment, intersection, or ramp data.
- Crash Data: crash location, date, collision type, severity, relationship to junction, maneuvers by involved vehicles (straight ahead/left turn/right turn/etc.)
- Roadway Segment Characteristics Data: segment number, segment location (mapped to crash locations), segment length (mi), area type (rural/urban), number of through traffic lanes (by direction of travel), median type (divided/undivided), access control (freeway/ non-freeway), two-way vs. one-way operation, traffic volume (AADT).
- Intersection Characteristics Data: intersection intersection number, intersection location (mapped to crash locations), area type (rural/urban), number of intersection legs, type of intersection traffic control, major-road traffic volume (AADT), minor-road traffic volume (AADT).
- Ramp Characteristics Data: ramp number, ramp location (in a form that is linkable to crash locations), area type (rural/urban), ramp length (mi), ramp type (on-ramp/off-ramp/freeway-to-freeway ramp), ramp configuration (diamond/loop/directional), ramp traffic volume (AADT).