Development of a speed-based surrogate roundabout safety measure
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F44994575%3A_____%2F16%3AN0000057" target="_blank" >RIV/44994575:_____/16:N0000057 - isvavai.cz</a>
Result on the web
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DOI - Digital Object Identifier
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Alternative languages
Result language
angličtina
Original language name
Development of a speed-based surrogate roundabout safety measure
Original language description
(Presented at 29th ICTCT workshop in Lund) Speed is one of the fundamental characteristics of traffic flow and also one of the most influential risk factors – it is therefore important from the perspective of safety-related studies. For these purposes speed data are often collected by stationary radars. However, since free-flow speed is usually needed, the user has to distinguish between free-flow and congested conditions in the collected data. Although this problem has long been acknowledged, there is no single and simple approach towards it; various authors have used different threshold definitions and values. In this regard, the authors aimed to investigate the amount of difference between free-flow and congested speeds, using a series of stationary radar speed surveys on Czech rural roads. It was found that difference (in terms of vehicle gaps) between free flow speed and car-following speeds is of concern; in addition, the magnitude of these differences is not constant as suggested in previous studies. It was also shown that there is a positive relationship between the gaps and accident rates in the studied road sections. These findings should be considered in future analyses which aim to obtain unbiased results of speed and its derivatives such as a proportion of speeding for safety-related analyses.
Czech name
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Czech description
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Classification
Type
O - Miscellaneous
CEP classification
JO - Land transport systems and equipment
OECD FORD branch
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Result continuities
Project
<a href="/en/project/ED2.1.00%2F03.0064" target="_blank" >ED2.1.00/03.0064: Transport R&D Centre</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2016
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů