FREEWAY OPERATIONS ON THE GULF FREEWAY RAMP CENTRAL SYSTEM

FREEWAY ENTRANCE RAMP CONTROL HAS BEEN SHOWN TO BE AN EFFECTIVE MEANS OF IMPROVING PEAK PERIOD LEVEL OF SERVICE ON THE INBOUND LANES OF THE GULF FREEWAY IN HOUSTON. RAMP CONTROL BEGAN ON THE GULF FREEWAY ON A DAY-TO-DAY BASIS IN 1965 AFTER SEVERAL YEARS OF INVESTIGATION, FORMULATION, TESTING, AND EVALUATION OF CONTROL THEORIES AND TECHNIQUES. CONTROL STRATEGIES EMPLOYED HAVE PROGRESSED THROUGH SEVERAL LEVELS OF SOPHISTICATION. THE CONTROL SYSTEM IMPLEMENTED IN 1965 CONSISTED OF EIGHT RAMP SIGNALS OPERATED MANUALLY AT A PREDETERMINED RATE BY A MAN AT EACH RAMP. TWO PROTOTYPE ANALOG CONTROLLERS WERE INSTALLED ON THE TELEPHONE ROAD RAMP IN 1966 TO EVALUATE THE CAPACITY-DEMAND AND GAP-ACCEPTANCE THEORIES OF RAMP METERING. KNOWLEDGE GAINED FROM THE PROTOTYPES LED TO THE INSTALLATION IN 1967 OF A COMPLETELY AUTOMATIC ANALOG CONTROL SYSTEM. THIS AND SUBSEQUENT CONTROL SYSTEMS WERE TRAFFIC RESPONSIVE, USING NUMEROUS VEHICLE SENSORS LOCATED ON RAMPS AND FREEWAY LANES. A CLOSED CIRCUIT TELEVISION SYSTEM COVERING A 6 1/2-MILE LENGTH OF FREEWAY WAS INSTALLED IN 1967. THE TELEVISION SYSTEM IS USED AS A RESEARCH AND STUDY TOOL FOR THE EVALUATION OF CONTROL SYSTEMS AND DOES NOT SERVE AS PART OF THE RAMP CONTROL SYSTEM. IT IS USED FOR OBSERVATION AND REPORTING OF FREEWAY INCIDENTS. IMPROVEMENT IN THE PEAK PERIOD LEVEL OF SERVICE HAS FOSTERED A SIGNIFICANT REDUCTION IN PEAK PERIOD ACCIDENTS, DURING A PERIOD WHEN TOTAL ACCIDENTS ON THE GULF FREEWAY INCREASED. INSTALLATION OF THE RAMP CONTROL SYSTEM HAS RESULTED IN A REDUCTION IN CONTROL PERIOD ACCIDENTS OF TWENTY-SEVEN PERCENT. RAMP SIGNALS, LIKE OTHER TRAFFIC CONTROL DEVICES, ARE NOT OBEYED BY ALL MOTORISTS. RAMP SIGNAL VIOLATIONS ON THE CONTROLLED RAMP VARY FROM FOUR TO THIRTEEN PERCENT.

• Supplemental Notes:
  • Summary RepT 24-25 (S), 2 PP
• Corporate Authors:

  Texas Transportation Institute

  Texas A&M University System, 1600 E Lamar Boulevard
  Arlington, TX  United States  76011
• Publication Date: 1969-8

Subject/Index Terms

• TRT Terms: Closed circuit television; Freeway operations; Freeways; Gap acceptance; Highway capacity; Peak hour traffic; Ramps; Ramps (Interchanges); Traffic control; Traffic control devices; Traffic crashes; Traffic signal controllers; Traffic signals
• Uncontrolled Terms: Violations
• Old TRIS Terms: Freeway entrances and exits; Freeway ramps; Freeway traffic accidents; Metering; Traffic control systems
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00225691
• Record Type: Publication
• Files: TRIS
• Created Date: May 19 1970 12:00AM