Speed prediction models for heavy passenger vehicles on rural highways based on an instrumented vehicle study

ABSTRACT

This study developed operating speed prediction models on tangents, curves, and tangent-to-curve transitions for heavy passenger vehicles (HPVs), using continuous speed profiles. Continuous speed profile data for HPVs were collected on two-lane rural highway sections, spanning a total length of 77 km. The curve radius, degree of curve, and preceding tangent length were found to be the influencing variables in predicting both the operating speed on the horizontal curves and the operating speed differential from tangent-to-curve transitions. The study also modeled the relationship between the differential of the 85^th percentile operating speed $(\mathrm{\Delta }{V}_{85})$ and 85^th percentile operating speed differential $\left({\mathrm{\Delta }}_{85}V\right)$. The analysis results from empirical data revealed that $\mathrm{\Delta }{V}_{85}$ underestimates ${\mathrm{\Delta }}_{85}V$ by 5.01 km/h. The reliability of the developed models was validated and compared with existing models from literature. The study highlights the significance of using continuous speed profile data to calibrate the operating speed models.

KEYWORDS:

• Continuous speed data
• design consistency
• heavy vehicles
• operating speed
• rural highways

Disclosure statement

No potential conflict of interest was reported by the authors.