00756240

Component

https://doi.org/10.3141/1646-06

http://scholar.google.com...shna&publication_year=1998

The capacity for right turns into gaps at signalized intersections, through right turn on red (RTOR) and free rights (with yield control), is examined. Current treatments provided by the "Highway Capacity Manual" (HCM), SIDRA, and a stop sign analogy (SSA) are examined. An adjustment to the SSA to eliminate capacity from gaps greater than the unsaturated flow period of the conflicting traffic is then described. The capacity for right turns into gaps is measured through a field study of seven right-turn-only lanes. The measured capacities are then compared with predicted capacities from the SSA and the adjusted stop sign analogy (ASSA). The data indicate that the HCM procedure to estimate RTOR volumes may not properly estimate those volumes. The SSA procedure tends to overestimate right-turn capacity by ignoring the effect of short phase lengths. The ASSA procedure provides lower estimates of capacity than the SSA, but may underestimate capacity. The results of the study can significantly increase the accuracy and usefulness of signalized intersection analysis by helping to answer questions about right-turn capacity, which now cannot be adequately addressed.

This paper appears in Transportation Research Record No. 1646, Highway Capacity Issues 1998.

English

p. 47-53

1998

Transportation Research Record

0309065186

Figures (4) ; References (9) ; Tables (7)

Alternatives analysis; Field studies; Forecasting; Highway capacity; Right turn on red; Right turns; Signalized intersections

Highway Capacity Manual

Field data

Highways; Operations and Traffic Management; I71: Traffic Theory

TRIS, TRB, ATRI

Nov 18 1998 12:00AM

• ACCURACY AND PERFORMANCE OF IMPROVED SPEED-FLOW CURVES
• ANALYSIS OF TWO LEFT-TURN EQUATIONS FROM THE "HIGHWAY CAPACITY MANUAL"
• BACKGROUND FOR HCM SECTION ON ANALYSIS OF PERFORMANCE OF ROUNDABOUTS
• DETERMINING IMPACT OF ROAD LIGHTING ON MOTORWAY CAPACITY
• EFFECT OF BICYCLES ON CAPACITY OF SIGNALIZED INTERSECTIONS
• EFFECT OF PEDESTRIANS ON CAPACITY OF SIGNALIZED INTERSECTIONS
• ESTIMATION OF PERCENTAGE OF DELAYED VEHICLES BASED ON TRAFFIC VARIABLES FOR RURAL HIGHWAYS
• EXTENSION AND APPLICATION OF PROSSER-DUNNE MODEL TO TRAFFIC OPERATION ANALYSIS OF OVERSATURATED, CLOSELY SPACED SIGNALIZED INTERSECTIONS
• FIELD MEASUREMENT OF SIGNALIZED INTERSECTION DELAY FOR 1997 UPDATE OF THE "HIGHWAY CAPACITY MANUAL"
• NEW ESTIMATION TECHNIQUE FOR VEHICLE-TYPE-SPECIFIC HEADWAY DISTRIBUTIONS
• PHASE CAPACITY CHARACTERISTICS FOR SIGNALIZED INTERCHANGE AND INTERSECTION APPROACHES
• QUEUEING AT CONGESTED INTERSECTIONS
• SAFETY, DELAY, AND CAPACITY OF SINGLE-LANE ROUNDABOUTS IN THE UNITED STATES
• SIMPLE, GENERALIZED METHOD FOR ANALYSIS OF TRAFFIC QUEUE UPSTREAM OF A BOTTLENECK
• SIMULATION STUDIES OF TRAFFIC OPERATIONS AT OVERSATURATED, CLOSELY SPACED SIGNALIZED INTERSECTIONS