TRAFFIC SIGNALS AND OVERHEAD FLASHERS AT RURAL INTERSECTION: THEIR EFFECTIVENESS IN REDUCING ACCIDENTS

TWO SPECIFIC TYPES OF OPERATIONAL IMPROVEMENTS-OVERHEAD FLASHERS AND TRAFFIC SIGNALS INSTALLED AT LOW-VOLUME, HIGH- SPEED RURAL INTERSECTIONS-WERE SELECTED FOR INVESTIGATION. THE EFFECTIVENESS OF THE DEVICES IN REDUCING TRAFFIC ACCIDENTS WAS EARMARKED AS THE PRIMARY OBJECTIVE OF THE ANALYSIS. INITIALLY, ALL FLASHERS AND SIGNAL DEVICES INSTALLED IN NORTH CAROLINA SINCE 1965 WERE CONSIDERED,BUT SUBSEQUENT INVESTIGATION AND A MORE RESTRICTIVE DEFINITION OF A TEST SITE REDUCED THE ORIGINAL INVENTORY FROM 72 FLASHERS AND 153 SIGNALS TO 14 FLAHSERS AND 19 SIGNALS. A BEFORE AND AFTER STUDY WAS MADE ENCOMPASSING MINIMUM TIME FRAMES OF 1 YEAR PRIOR TO AND IMMEDIATELY AFTER INSTALLATION OF THE DEVICE. ACCIDENT EXPOSURE DURING THE TWO PERIODS WAS COMPARED ON THE BASIS OF EXPOSURE RATES, SEVERITY INDEXES, AND EQUIVALENT PROPERTY DAMAGE ONLY ACCIDENTS AND RATES. IT WAS DETERMINED THAT THE EQUIVALENT PROPERTY DAMAGE ONLY RATE, RATHER THAN THE NORMALLY USED ACCIDENT RATE, WAS THE MOST RELIABLE AND SIGNIFICANT INDICATOR OF ACCIDENT CONSEQUENCES. IF ALL OTHER FACTORS WERE CONSTANT, ANY SIGNIFICANT CHANGE IN RATE AFTER INSTALLATION OF THE CONTROL DEVICE COULD BE ATTRIBUTED TO THE PRESENCE OF THE DEVICE. THE RELATIONSHIP BETWEEN THE INSTALLATION OF SIGNALS AND EQUIVALENT PROPERTY DAMAGE ONLY RATE REDUCTION WAS NOT STATISTICALLY SIGNIFICANT EXCEPT FOR UNDIVIDED HIGHWAY INTERSECTIONS. THE RELATIONSHIP BETWEEN THE INSTALLATION OF A FLASHING BEACON AND RATE REDUCTION WAS FOUND TO BE STATISTICALLY SIGNIFICANT AT THE 1 PERCENT CONFIDENCE LEVEL. /AUTHOR/

• Supplemental Notes:
  • Paper sponsored by Committee on Traffic Control Devices and presented at the 49th Annual Meeting.
• Authors:
  • Cribbins, Paul D
  • Walton, C Michael
• Publication Date: 1970

Media Info

• Media Type: Print
• Features: Figures; References; Tables;
• Pagination: pp 1-14
• Monograph Title: Traffic signals and signs
• Serial:
  • Highway Research Record
  • Issue Number: 325
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Beacons; Before and after studies; Flashing beacons; Intersections; Loss and damage; Prevention; Property; Rural highways; Safety; Traffic signals
• Uncontrolled Terms: Property damage
• Old TRIS Terms: Overhead traffic signals
• Subject Areas: Highways; Safety and Human Factors; Security and Emergencies;

Filing Info

• Accession Number: 00221173
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Feb 12 1971 12:00AM