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Speed change behavior on combined horizontal and vertical curves: driving simulator-based analysis
1College of Transportation Engineering, Tongji University, Shanghai 201804, China.
Accident; Analysis and Prevention
|July 28, 2018
Summary
Driver speed changes on freeway combined curves vary significantly by curve type and adjacent road design. Understanding these differences is crucial for improving road safety and planning effective highway alignments.
Area of Science:
- Transportation Engineering
- Road Safety
- Traffic Behavior Analysis
Background:
- Combined horizontal and vertical curves on freeways can negatively impact driver speed control, posing safety risks.
- Existing research often treats combined curves generically, potentially overlooking critical variations in driver behavior.
Purpose of the Study:
- To investigate and differentiate driver speed change behaviors across four specific types of combined road curves (downslope, upslope, crest, sag).
- To analyze the influence of geometric design characteristics of combined curves and their adjacent segments on driver speed adjustments.
Main Methods:
- Utilized a driving simulator programmed with 70 combined curves from a mountainous freeway design.
- Collected vehicle operation data from participants driving through simulated scenarios.
- Employed multinomial logit models to analyze speed change behaviors (substantial decrease, steady speed, substantial increase) and their determinants.
Main Results:
- Frequency of speed change behaviors varied significantly among the four combined curve types.
- Geometric design features had distinct and varying effects on speed changes depending on the specific combined curve type.
- Design characteristics of road segments adjacent to combined curves also exerted significant and differential impacts on driver speed.
Conclusions:
- Combined curves necessitate individual analysis rather than a generalized approach.
- Incorporating the design of adjacent road segments into the planning of combined curves is essential for enhancing freeway safety.
Keywords:
Adjacent segmentCombined horizontal and vertical curvesDriving simulatorMultinomial logit modelSpeed change behaviorMore Related Videos
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