Effect of weather conditions to traffic flow on freeway
- 456 Downloads
Traffic speed along a roadway segment is the function of a number of factors like geometry, traffic and weather conditions. In this paper, the effect of weather conditions both the speed-flow and flow-occupancy relationships was studied. The data used in the analysis were obtained from traffic management system installed in the Incheon International Airport Expressway. In order to quantify how seriously weather affects traffic flow conditions, the impact in term of traffic speed was described. Regression analyses were performed to select proper models representing the speed-flow and flow-occupancy relationship for uncongested operation. From the research, weather conditions reduced the slope of flow-occupancy function and caused a downward shift in the speed-flow function. That is, the free flow speeds are reduced. Increase of traffic volume by weather event at the YeongJong Grand Bridge (site2) is much larger than at the BwangHwa Grand Bridge (sitel), which makes travel speed down significantly. The ratio of free flow speed reduction was observed 7% and 2% by snowy and rain, respectively. Meanwhile, the ratio of speed reduction was shown that snowy and rainy night are each 5% and 6% drop. That is, the effect of snowy day and night is similar while the effect of rainy night is larger than rainy day in terms of speed redution In case of site 2, during day time, the ratio of speed reduction was turned out no difference according to weather events like snowy and rainy conditions. However, the ratio of speed reduction during night time was decreased 3% and 7% in each snowy and rainy conditions.
KeywordsITS RWIS speed reduction traffic flow weather effect
Unable to display preview. Download preview PDF.
- Al-kaisy and Hall, F.L. (2000). “Effect of darkness on the Capacity of long-term freeway reconstruction zones.”Proceeding of 4th international symposium on highway capacity, Maui, Hawaii.Google Scholar
- Choi Joung-sun, Son Bong-su, Choi Jai-sung (1993). “The Effect of rain on Traffic flows in Urban Freeway Basic Segments.”Korean Society of Transportation, Vol. 17, No. 1.Google Scholar
- Enberg, A. and Mannan, S. (1998). “Effects of Road and Weather Conditions on Traffic flow on a Three-Lane Rural Highway in Finland.”Xth PIARC International Winter Road Congress, Lulea, Sweden.Google Scholar
- Hall, F.L. and Ibrahim, A.T. (1994). “Effect of Adverse Weather Condition on Speed-Occupancy Relationships.”Transportation Research Record, 1457, pp. 184–191.Google Scholar
- Hogema, J.H. (1996).Effects of Rain on Daily Traffic Volume and on Driving Behavior, Delft Hydraulics Laboratory. The Netherlands.Google Scholar
- Korean National Police Agency (1999).The White Paper on road traffic safety, pp. 289–300.Google Scholar
- Kang Byong-seu, Kim Kea-Sun (1998).Social Science Statistics, Spss Academy.Google Scholar
- Kyte, M., Khatib, M., Shannon P., Kitchener, F. (2000). “Effect of Environmental Factors on Free-Flow Speed.”Proceeding of 4th international symposium on highway capacity, Maui, Hawaii.Google Scholar
- Ministry of construction & transportation,National ITS Architecture (II), (1999).Google Scholar