Preliminary Validation of a Speed-Profile Model for Design Consistency Evaluation

The validity of a speed-profile model for design consistency evaluation was tested, including (a) the speed reduction estimation ability of the model and (b) assumptions about deceleration and acceleration characteristics approaching and departing horizontal curves. Detailed speed data were collected at a sample of 10 horizontal tangent-curve sections on two-lane rural highways in Texas. The results indicate that the model provides a reasonable, albeit simplified, representation of speed profiles on horizontal alignments consisting of long tangents and isolated curves. The model provides reasonable estimates of speed reductions from long approach tangents to curves but does not account for the effect of nearby intersections on speeds. The results also indicate that the assumed 0.85 m/sec2 value is reasonable for deceleration rates approaching curves that require speed reductions but may overestimate acceleration rates departing curves. The model's assumptions that deceleration occurs entirely on the appro...

[1]  T H Rockwell,et al.  DEMONSTRATION OF A TEST-DRIVER TECHNIQUE TO ASSESS THE EFFECTS OF ROADWAY GEOMETRICS AND DEVELOPMENT ON SPEED SELECTION , 1971 .

[2]  H T Thompson,et al.  ACCIDENT SURROGATES FOR USE IN ANALYZING HIGHWAY SAFETY HAZARDS VOLUME II-TECHNICAL REPORT , 1983 .

[3]  G Mintsis SPEED DISTRIBUTIONS ON ROAD CURVES , 1988 .

[4]  D J Segal,et al.  EVALUATION OF HORIZONTAL CURVE DESIGN , 1980 .

[5]  Tim Neuman,et al.  ANALYSIS OF VEHICLE OPERATIONS ON HORIZONTAL CURVES , 1991 .

[6]  C J Messer,et al.  HORIZONTAL ALIGNMENT DESIGN CONSISTENCY FOR RURAL TWO-LANE HIGHWAYS. FINAL REPORT , 1995 .

[7]  C H Lee A study into driver speed behaviour on a curve by using continuous speed measurement method , 1988 .

[8]  E M Choueiri,et al.  RURAL ROADS SPEED INCONSISTENCIES DESIGN METHODS. PART 1. OPERATING SPEEDS AND ACCIDENT RATES ON TWO-LANE RURAL HIGHWAY CURVED SECTIONS: INVESTIGATIONS ABOUT CONSISTENCY AND INCONSISTENCY IN HORIZONTAL ALIGNMENT , 1987 .

[9]  M R Parker,et al.  AN EVALUATION OF ACCIDENT SURROGATES FOR SAFETY ANALYSIS OF RURAL HIGHWAYS. FINAL REPORT. VOLUME I. EXECUTIVE SUMMARY , 1986 .

[10]  Claes Holmquist Changes in speeds of vehicles on horizontal curves , 1970 .

[11]  Joel P Leisch,et al.  New concepts in design-speed application , 1977 .

[12]  E M Choueiri,et al.  A DESIGN PROCEDURE TO DETERMINE CRITICAL DISSIMILARITIES IN HORIZONTAL ALIGNMENT AND ENHANCE TRAFFIC SAFETY BY APPROPRIATE LOW-COST OR HIGH-COST PROJECTS. FINAL REPORT , 1987 .

[13]  H T Thompson,et al.  ACCIDENT SURROGATES FOR USE IN ANALYZING HIGHWAY SAFETY HAZARDS VOLUME I-EXECUTIVE SUMMARY , 1983 .

[14]  Timothy R Neuman,et al.  SAFETY AND OPERATIONAL CONSIDERATIONS FOR DESIGN OF RURAL HIGHWAY CURVES. FINAL REPORT , 1983 .

[15]  M R Parker,et al.  AN EVALUATION OF ACCIDENT SURROGATES FOR SAFETY ANALYSIS OF RURAL HIGHWAYS. FINAL REPORT. VOLUME II. TECHNICAL REPORT , 1986 .

[16]  J A Reagan The Interactive Highway Safety Design Manual: designing for safety by analyzing road geometrics , 1994 .

[17]  A Taragin,et al.  DRIVER PERFORMANCE ON HORIZONTAL CURVES , 1954 .