00781506

Component

https://doi.org/10.3141/1690-05

http://scholar.google.com...nnis&publication_year=1999

Concerns about the Hutchinson and Kennedy (H&K) encroachment data used as the basis for the American Association of State Highway and Transportation Officials' (AASHTO's) Roadside Design Guide (RDG) procedures for computing guardrail runout length have led to proposed revised guidelines based on more recent data collected by Cooper in Canada. The revised guidelines result in guardrail lengths that are approximately 35% shorter. Data from the original H&K and Cooper studies were analyzed to determine why the two studies seem to have inconsistent findings. The concerns about the H&K data expressed by the authors who proposed the revised guidelines were found to be invalid. However, team-by-team comparisons of the Cooper data revealed inconsistencies in encroachment rates, lengths, and departure angles for highways with similar speed limits. Documented data collection problems and unanswerable questions about the methodology used to measure encroachment lengths and departure angles make it impossible to validate the accuracy of the Cooper data. Adjustments were made to the Cooper data to compensate for possible data irregularities to examine the consistency between them and the H&K data. No evidence indicating that the encroachment lengths reported by H&K are inconsistently high compared with the encroachment lengths reported by Cooper was found. The findings suggest that reducing guardrail runout lengths from current RDG guidelines for highways with high speed limits [112 km/h (70 mph)] may not be prudent.

This paper appears in Transportation Research Record No. 1690, Roadside Safety and Other General Design Issues.

English

Cooper, P J; SANDERSON, R W; Sicking, D L

p. 42-58

1999

Transportation Research Record

0309071208

Figures (7) ; References (10) ; Tables (6)

Guardrails; Length; Roadside; Speed limits

Encroachment; Field data

Design; Highways; Safety and Human Factors; I85: Safety Devices used in Transport Infrastructure

TRIS, TRB

Jan 19 2000 12:00AM

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• CONNECTING MINNESOTA: SUPERHIGHWAYS TO INFORMATION SUPERHIGHWAYS
• CRASHWORTHINESS OF ROADSIDE FEATURES ACROSS VEHICLE PLATFORMS
• DEVELOPMENT OF A FLARED END TERMINAL THAT MEETS CRITERIA OF NCHRP REPORT 350: THE REGENT SYSTEM
• DEVELOPMENT OF A FLARED ENERGY-ABSORBING TERMINAL FOR W-BEAM GUARDRAILS
• EFFECTS OF COHESIVE MATERIAL PROPERTIES ON LOCAL SCOUR AROUND PIERS
• EFFECTS OF POST AND SOIL STRENGTH ON PERFORMANCE OF MODIFIED ECCENTRIC LOADER BREAKAWAY CABLE TERMINAL
• FACTORS RELATED TO PROBABILITY OF JOINT FLOODING ON PAIRED STREAMS IN OHIO
• HEAVY-GOODS VEHICLE COLLISIONS WITH STEEL ROAD SAFETY BARRIERS: COMBINED INFLUENCES OF POSITION OF CENTER OF MASS AND TIRE-PAVEMENT FRICTION
• HYDRODYNAMIC COUNTERMEASURES FOR LOCAL PIER SCOUR
• INFRASTRUCTURE INVENTORY AND CONDITION ASSESSMENT USING AIRBORNE LASER TERRAIN MAPPING AND DIGITAL PHOTOGRAPHY
• RESOURCE SHARING: WIRELESS TELECOMMUNICATIONS SITE LEASE RATES
• REUSABLE HIGH-MOLECULAR-WEIGHT, HIGH-DENSITY POLYETHYLENE CRASH CUSHIONS FOR WIDE HAZARDS
• ROADSIDE SAFETY ANALYSIS PROGRAM AS A TOOL FOR ECONOMIC EVALUATION OF ROADSIDE SAFETY PROJECTS (WITH DISCUSSION AND CLOSURE)
• SOME EXPERIENCE WITH GEOSPATIAL IMAGERY AND ROUTE OPTIMIZATION
• SURVEYOR: MOBILE HIGHWAY INVENTORY AND MEASUREMENT SYSTEM
• TWO-DIMENSIONAL MODELING OF COLLISION DYNAMICS OF DEFLECTING CONCRETE BARRIERS
• USING LS-DYNA SIMULATION TO SOLVE A DESIGN PROBLEM: BULLNOSE GUARDRAIL EXAMPLE
• VARIATION IN CHARACTERISTICS OF ABRADED ROADWAY PARTICLES AS A FUNCTION OF PARTICLE SIZE: IMPLICATIONS FOR WATER QUALITY AND DRAINAGE
• VIDEOLOG ASSESSMENT OF VEHICLE COLLISION FREQUENCY WITH CONCRETE MEDIAN BARRIERS ON AN URBAN HIGHWAY IN CONNECTICUT