Collision Report Database

Date Submitted: May 5, 2011 Submitted By: Patricia Fyhrie
Challenge Area: 14: Work Zone Accident Report Database (WZARDB)
Summary Description: Over 2400 California Highway Patrol (CHP) 555 Traffic Collision Reports have been collected, processed and input into a database. CHP555 reports from traffic accidents occurring near a work zone have been collected from Districts 3,4 and 10 for the years 2006-2008. This summary describes briefly what data resides within this database, some of the data analysis performed so far, what the web page interface can provide, and the plans for future development.
Database Details:

  • 2400 CHP555 Processed; a subset from a possible 18,000 from the entire state of CA (years 2006-2008). Under the Road Condition Section, these reports state “Construction – Repair Zone” as one of the road conditions.
  • The subset of collected reports are from Districts 3, 4, and 10 due to their close proximity to UC Davis
  • All TASAS information available from the database for all 18,000 possible reports are:
Post Mile
Highway Group
Access Control
Median Type
Barrier Type
Number Of Lanes Left
Number Of Lanes Right
Population Code
File Type
Intersection / Ramp Accident Location
Side Of Highway
Day Of Week
Accident Date
Accident Time
Accident Number
Primary Collision Factor
Roadway Surface
Roadway Condition
Right Of Way Control
Type Of Collision
Number Of Motor Vehicles Involved
Party Type
Direction Of Travel
Vehicle Highway Indicator
Special Information
Persons Killed
Persons Injured
Primary Object Struck Location
A Other Object Struck Location
B Other Object Struck Location
C Other Object Struck Location
Other Associated Factor
Movement Preceding Collision Location
Sobriety Drug Physical
  • In addition to the above, the AHMCT database also provides detailed information from the processed 2400 reports including:
    • Injury information (severity and cost)
    • Specific factors and outcomes as well as general (“Summary”) factors and outcomes
    • Where in the work zone did the accident occur (e.g. activity area, transition, etc.) and whether there was any intrusion into the activity area
    • Detailed accident description and traveling speed of involved motorists.
Selected Analysis Results:Although many different analyses are possible with this database, a few have been selected and shown here:

  • The cost due to injuries from highway accidents where work zone was present is approximately $800 million.
  • Improper driving, Inattention , and “Too Fast/Too Close” each contribute about 30% of all accidents in work zones with the remaining 10% distributed amongst other factors such as drunk driving.
  • Majority of accidents (67%) occur within the activity area
  • The most frequent outcome is a rear end collision although only minor or no injuries occur in almost all of the occurrences.
Web-Based Interface: Designated Caltrans personnel can access the data through: capabilities can be assigned by AHMCT, the originators of this database.

  • As of 5May2011, Login information can be obtained from Patricia Fyhrie All questions can be directed to her. Contact phone: 530-312-9026.
  • The main menu on the left hand side allows the user to select and search through the database. Comparisons between frequency and cost is available as well as finding correlations between factors and outcomes. Injury information can also be seen and how it is distributed amongst summary factors and outcomes.

Future Work:We have proposed to expand upon the content of the database by extending the data collections to the rest of the Caltrans districts. Accident report collection and processing to date has not included southern California. Whether or not the difference in traffic demographics will affect the outcome cannot be determined until a sufficient amount of comparative data has been collected and analyzed.In addition to collecting accident reports from southern CA, we also intend to expand the current set of reports from Districts 3,4 and 10 to include 2009 and 2010 data. Plans also include expanding the web page interface to show diagrams of traffic collisions of particular interest (when available). We are investigating whether we can digitize particular attributes (e.g. ramp, intersection, etc.) into a searchable format and see if there are correlations between accident locations for example, and a particular outcome.

Other capabilities being planned are showing the relationships between time of day, holidays and the prevalence of drunk driving causing accidents within a work zone. Also, we wish to know whether construction or maintenance work zones play a factor in causing or preventing frequency of accidents. Knowing predominance (if any) of accidents in construction vs. maintenance would be beneficial and thus dedicate appropriate resources towards reducing the frequency.

Other ideas are continually being suggested and investigated through the CA14 committee in an effort to make work zones safer for both motorists and the workers on the road. One area we hope to use the database is to evaluate traffic patterns such as speed fluctuations on accident statistics. of speeds and whether there is anything we can do within Caltrans to reduce unexpected braking or erratic driving.

Lead Agency: Caltrans. Action Lead: Kamal Sah
Other Agencies: Other agencies that are critical to the successful implementation are the California Highway Patrol, and the Advanced Highway Maintenance and Construction Technology Research Center (AHMCT) in Davis. Key People: Mary Uhazi from CHP, Patricia Fyhrie from AHMCT, Davis
Costs to Implement & Other Resources: Estimated cost to complete the Action is $600,000 : Medium = $250,000 to less than $1,000,000
Risks/Barriers to Success & Mitigation Strategies: The success of this Action is dependent on being able to access the Traffic Collision Coding Injury Reports (CHP 555). If permission is not granted to work with CHP to review and analyze the data from the 555’s, it would be to the detriment of the SHSP program specifically CA#14, “Enhance Work Zone Safety. To avoid this catastrophe, CHP should be involved in every way possible so we can ensure their continuous support.
Steering Committee Recommendation Date: Executive Committee Approval Date: