This Excel application presents a method for field surveys of Critical Gap (Headway) and Follow-up Headway which are the key parameters in the SIDRA gap acceptance capacity and performance models for roundabouts, intersections controlled by two-way stop and give-way / yield signs and unsignalised pedestrian crossings. The method can also be used for opposed (permitted / filter turn) movements at signalised intersections. For model calibration and validation purposes, the gap acceptance survey method needs to match the Critical Gap (Headway) and Follow-up Headway definitions used by the model. This survey method is recommended for calibration and validation of SIDRA Critical Gap (Headway) and Follow-up Headway estimates.
The INTRODUCTION sheet of the application gives information on the survey method. Detailed information on gap acceptance modelling is included in the SIDRA INTERSECTION User Guide.
AKÇELIK, R. (2021). SIDRA Gap Acceptance Survey (Excel Application SIDRA_GAP-ACCEPTANCE-SURVEY.xlsx). Akcelik and Associates Pty Ltd, Melbourne, Australia.