How does rain affect traffic performance indicators?
BILLOT ; EL-FAOUZI ; SAU ; DE VUYST
Type de document
COMMUNICATION AVEC ACTES INTERNATIONAL (ACTI)
Langue
anglais
Auteur
BILLOT ; EL-FAOUZI ; SAU ; DE VUYST
Résumé / Abstract
The proactive traffic operations for real-time traffic management involve a better knowledge of road weather conditions. In this way, the assessment of the effects of inclement weather conditions constitutes a critical issue not only at a mobility level but also at a safety level: various studies exhibit noticeable effects of weather conditions on traffic crashes in terms of severity and frequency. With regard to traffic flow, speed and density and in spite of an expansion in the recent years, comprehensive studies of weather impacts on traffic are still seldom. Consequently, existing traffic management tools do not take into account the effects of weather conditions. In a previous study (1), we proposed a comprehensive framework for the integration of the weather effects into a traffic management strategy. The first step is to quantify the weather impact through data analysis. Such studies will enable an improvement of the traffic stream models in order to integrate weather conditions impacts. In this paper, an investigation of the effects of rain on a French urban highway section is carried out. The considered section is the Eastern part of Lyon's ring road, located just near Lyon-Bron Airport, which provides weather data. The one-minute aggregated data were collected from 16 loop detectors. Through a calibration of macroscopic traffic flow model, the results show an impact of rain on the speed as well as on density and capacity. Moreover, the explicit integration of weather information in the macroscopic traffic models shows a better consistency between measured and estimated characteristics. These significant results pave the way for an integration of those effects in the traffic flow models and a development of new weather-responsive traffic performance indicators to be used for traffic management operations. An example of such an integration of the weather impact into areal-time traffic management is proposed through a simulation case.
