Data Requirements

The SafetyAnalyst software tools require access to a database of roadway characteristics, traffic volume, and crash data for an agency’s road network. Many of the data elements required for SafetyAnalyst are readily available to highway agencies, but some effort to assemble other data elements may be needed. SafetyAnalyst includes a data management tool to help users import and manage these data. While many additional data elements are desirable for SafetyAnalyst and may be evaluated, the minimum set of data elements required to use SafetyAnalyst includes:

Roadway Segment Characteristics Data

• Segment number
• Segment location (in a form that is linkable 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/nonfreeway)
• Two-way vs. one-way operation
• Traffic volume (AADT)

Intersection Characteristics Data

• Intersection number
• Intersection location (in a form that is linkable to crash locations)
• Area type (rural/urban)
• Number of intersection legs
• Type on 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/etc.)
• Ramp traffic volume (AADT)

Crash Data

• Crash location
• Date
• Collision type
• Severity
• Relationship to junction
• Maneuvers by involved vehicles (straight ahead/left turn/right turn/etc.)