00474257

Component

http://onlinepubs.trb.org...trr/1986/1069/1069-006.pdf

https://scholar.google.co...yton&publication_year=1986

Traffic signals affect the safety and efficiency of traffic operations. Flashing-signal operation reduces delays during low-volume periods and may conserve energy. However, flashing operation has been found to affect the safety of the intersection adversely. The relative accident impacts of flashing-signal operation versus regular signal operation in the city of Portland are evaluated. Analyses were conducted to determine whether an increase in accidents occurred at the intersections when the control devices were operated in the flashing mode during low-volume nighttime hours. For the intersections studied, the accident levels, volume levels, intersection geometry, and speed and parking data were collected. A statistical analysis was made to determine the safety of flashing operation for intersections with various volume ratios, street classifications, types of approaches, approach speed limits, and parking conditions. Intersections at which the major-street volumes were more than twice the minor-street volumes experienced a significant increase in accidents when flashing operation was used. Significant increases in accidents were also found when flashing signals were installed at intersections with major-street approach speeds in excess of 30 mph. Accidents also increased with flashing operation when both streets were two-way and where parking was allowed on both streets. Accident severity increased for many situations, often because there was an increase in right-angle accidents.

Publication of this paper sponsored by Committee on Traffic Control Devices. Publication of this paper sponsored by Committee on Traffic Control Devices. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

00490259

HS-040 095

pp 24-29

1986

Transportation Research Record

0-309-04063-9

Print

References (7) ; Tables (5)

Approach; Crash severity; Crashes; Energy conservation; Flashing traffic signals; Night; On street parking; Reduction (Chemistry); Right angle crashes; Speed; Statistical analysis; Traffic delays; Traffic safety; Traffic volume; Two lane highways

Two way traffic

Portland (Oregon)

Portland (Oregon)

Data and Information Technology; Energy; Environment; Highways; Operations and Traffic Management; Safety and Human Factors; I73: Traffic Control; I81: Accident Statistics

HSL, TRIS, TRB

Oct 31 1990 12:00AM

• A FURTHER NOTE ON UNDULATION AS A SPEED CONTROL DEVICE
• A PROBABILISTIC APPROACH FOR DETERMINING THE CHANGE INTERVAL (DISCUSSION AND CLOSURE)
• A REASSESSMENT OF THE TRAFFIC SIGNAL CHANGE INTERVAL
• ADAPTING THE U.S. DEPARTMENT OF TRANSPORTATION RAIL-HIGHWAY CROSSING RESOURCE ALLOCATION MODEL TO THE MICROCOMPUTER
• ANALYTICAL WARRANT FOR SEPARATE LEFT-TURN PHASING (ABRIDGMENT)
• COUNTERING SIGN VANDALISM WITH PUBLIC SERVICE ADVERTISING (ABRIDGMENT)
• CRITIQUE OF RAIL-HIGHWAY GRADE CROSSING EFFECTIVENESS RATIOS AND RESOURCE ALLOCATION PROCEDURES (DISCUSSION AND CLOSURE)
• EFFECTIVENESS OF FLASHING BEACONS IN REDUCING ACCIDENTS AT A HAZARDOUS RURAL CURVE (ABRIDGMENT)
• GUIDELINES FOR PROTECTED/PERMISSIVE LEFT-TURN SIGNAL PHASING
• GUIDELINES FOR SELECTING TYPE OF LEFT-TURN PHASING
• RUMBLE STRIPS AND PAINT STRIPES AT A RURAL INTERSECTION
• THE EFFECTS OF WIDE EDGE LINES ON LATERAL PLACEMENT AND SPEED ON TWO-LANE RURAL ROADS
• THE SAFETY, ECONOMIC, AND ENVIRONMENTAL CONSEQUENCES OF REQUIRING STOPS AT RAILROAD-HIGHWAY CROSSINGS
• THE USE OF CONSTANT WARNING TIME SYSTEMS AT RAIL-HIGHWAY GRADE CROSSINGS
• TIMING DESIGN OF SIGNAL CHANGE INTERVALS (DISCUSSION AND CLOSURE)
• TIMING DESIGN OF TRAFFIC SIGNALS
• VALIDATION OF A TRAFFIC MODEL