DOI QR코드

DOI QR Code

실험적 용량산정 방법 비교 연구

Comparing Empirical Methods of Highway Capacity Estimation

  • 투고 : 2013.09.13
  • 심사 : 2014.01.27
  • 발행 : 2014.02.17

초록

PURPOSES : Capacity is a main factor of determining the number of lane in highway design or the level of service in road on operation. Previous studies showed that breakdown may occur before capacity is reached, and then it was concluded that capacity is a stochastic value rather than a deterministic one. In general, estimating capacity is based on average over maximum traffic volume observed for capacity state. This method includes the empirical distribution method(EDM) and would underestimate capacity. This study estimated existing empirical methods of estimating stochastic highway capacity. Among the studied methods are the product limit method(PLM) and the selected method(SM). METHODS : Speed and volume data were collected at three freeway bottleneck sites in Cheonan-Nonsan and West Sea Freeway. The data were grouped into a free-flow state or capacity state with speeds observed in the bottlenecks and the upstream. The data were applied to the empirical methods. RESULTS : The results show that the PLM and SM estimated capacity higher than EDM. The reason is that while the EDM is based on capacity observations only, the PLM and SM are based on free-flow high volumes and capacity observations. CONCLUSIONS : The PLM and SM using both free-flow and capacity observations would be improved to enhance the reliability of the capacity estimation.

키워드

참고문헌

  1. Korea Highway Capacity Manual, 2013. Ministry of Construction & Transportation.
  2. Michiel M. Minderhoud, Hein Botma, and Piet H. L. Bovy(1997), Assessment of Roadway Capacity Estimation Methods, Transportation Research Record: Journal of the Transportation Research Board, No. 1572, pp. 59-67.
  3. Matt R. Lorenz and Lily Elefteriadou(2001), Defining Freeway Capacity as Function of Breakdown Probability, Transportation Research Record: Journal of the Transportation Research Board, No. 1776, pp. 43-51.
  4. Lily Elefteriadou, Roger P. Roess, and William R. McShane(1995), Probabilistic Nature of Breakdown at Freeway Merge Junctions, Transportation Research Record: Journal of the Transportation Research Board, No. 1484, pp. 80-89.
  5. Zhe Sun and Chao Yang(2011), Development of Extreme Value Distirbution Method for Estimation of Expressway Capacity, Transportation Research Record: Journal of the Transportation Research Board, No. 2260, pp. 133-139.