Preliminary communication
https://doi.org/10.7307/ptt.v32i1.3155
Estimation of Critical Headway at Small Urban Roundabout
Danijela Maslać
; University of Mostar, Faculty of Civil Engineering
Dražen Cvitanić
orcid.org/0000-0003-1151-6419
; University of Split, Faculty of Civil Engineering, Architecture and Geodesy
Ivan Lovrić
; University of Mostar, Faculty of Civil Engineering
Abstract
Before choosing an intersection project design, an important step is to examine the justification of the construction on the basis of defined criteria. One of the key criteria is the analysis of capacity. Large numbers of roundabout capacity models are present in the world, most of them adapted to the conditions of the country they originate from and they need to be calibrated for local conditions. Key parameters for calibration are critical headway and follow-up headway. Follow-up headway can be measured directly in the field, while critical headway cannot be measured, but is estimated. Many critical headway estimation methods exist (over 30) and each of them provides different values. Different values of critical headway result in different capacity estimation values. This raises the question which method provides more realistic estimations under certain conditions. In this paper, four most frequently used critical headway estimation methods (Raff, Maximum likelihood method, Wu, Logit) were selected to be tested by comparison of theoretical capacity models and actual measured capacity at a small urban roundabout.
Keywords
Hrčak ID:
234278
URI
Publication date:
27.1.2020.
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