The evaluation of geometric design consistency implies the preliminary estimation of operating speeds (V85), for which a number of predicting models can be found in literature, based on characteristics of the horizontal alignment and neglecting potential effects of the vertical ones. In this respect, we carried out an experimental survey using the interactive static base driving simulator of the Interuniversitary Research Center on Road Safety in order to evaluate how horizontal alignment and profile affect speed. Two two-lane rural roads were designed and implemented in the driving simulator. They are characterized by the same horizontal alignment but different vertical alignments: one is completely flat while the other has a profile with longitudinal grades ranging between ±6%. Collected data analysis during the simulation tests highlighted that: on the elements of the road with grades different than zero the V85s are different from those measured on the same elements of the flat road; V85 values measured on the road with longitudinal grades different than zero determine different evaluations from those determined by V85 measured on flat road on road safety, according to Safety Criterion II; the operating speed on each design element of the alignment is influenced also by the adjacent elements. According to the surveys carried out, here we are proposing some V85 predicting models for curve sections and tangents. An assessment is required on the basis of further data from tests on driving simulator on a wider sample of two-lane rural roads.

Bella, F. (2005). The evaluation of design consistency: predicting models of operating speed on three-dimensional alignment from tests on driving simulator. In Proceedings of the 3rd International Symposium on Highway Geometric Design. CHICAGO : Transportation Research Board.

The evaluation of design consistency: predicting models of operating speed on three-dimensional alignment from tests on driving simulator

BELLA, Francesco
2005-01-01

Abstract

The evaluation of geometric design consistency implies the preliminary estimation of operating speeds (V85), for which a number of predicting models can be found in literature, based on characteristics of the horizontal alignment and neglecting potential effects of the vertical ones. In this respect, we carried out an experimental survey using the interactive static base driving simulator of the Interuniversitary Research Center on Road Safety in order to evaluate how horizontal alignment and profile affect speed. Two two-lane rural roads were designed and implemented in the driving simulator. They are characterized by the same horizontal alignment but different vertical alignments: one is completely flat while the other has a profile with longitudinal grades ranging between ±6%. Collected data analysis during the simulation tests highlighted that: on the elements of the road with grades different than zero the V85s are different from those measured on the same elements of the flat road; V85 values measured on the road with longitudinal grades different than zero determine different evaluations from those determined by V85 measured on flat road on road safety, according to Safety Criterion II; the operating speed on each design element of the alignment is influenced also by the adjacent elements. According to the surveys carried out, here we are proposing some V85 predicting models for curve sections and tangents. An assessment is required on the basis of further data from tests on driving simulator on a wider sample of two-lane rural roads.
2005
Bella, F. (2005). The evaluation of design consistency: predicting models of operating speed on three-dimensional alignment from tests on driving simulator. In Proceedings of the 3rd International Symposium on Highway Geometric Design. CHICAGO : Transportation Research Board.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11590/179197
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