• Journal of Korean Society of Transportation
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• v.17 no.4
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• pp.19-31
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• 1999

A first version of KHCM was Published in 1992, and is currently used extensively in engineering Practice. The study of new manual was initiated in 1998 and is intended to be ready for publication by the year 2000. The purpose of this paper is to indicate the study direction of basic freeway section by comparing the results of each country HCM. 1985 USHCM, 1997 USHCM, 1992 K17CM, German HCM, Japan HCM, Australian HCM. Taiwan HCM, and Canadian HCM have been reviewed. All the country except Germany followed the same method developed in 1985 USHCM for analysing basic freeway section. Therefore the method of USHCM and German HCM have been introduced in detail. Finally. the Problem of 1992 KHCM have been suggested.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.287-293
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• 2008

Density is used as the measure of effectiveness within the ramp junction influence area suggested in the KHCM 2005 in the LOS analysis of the ramp junction, and also density predictive models suggested in the KHCM 2005 is constructed based on the expressway with the speed limit of 100km/h or 110km/h in Korea. So, the density predictive models suggested in the KHCM 2005 are needed to verify if the models could be applied to the urban freeway with the speed limit of 80km/h or less, because the speed limits on most of the urban freeways in Korea are 80km/h or less. The purpose in this study is to construct and verify the appropriate density predictive model within the on-ramp merge influence area of the urban freeway by comparing with the USHCM 2000 and KHCM 2005 models.

• International Journal of Highway Engineering
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• v.17 no.2
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• pp.123-134
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• 2015

PURPOSES : The key point of a multimodal LOS (level-of-service) evaluation system is that all of the modes are mutually associated to determine each mode's LOS. For example, the LOS of the bicycle mode is measured based on not only bicycle volumes, but also automobile volumes. However, the Korea Highway Capacity Manual (KHCM) still focuses on the automobile mode in evaluating the LOS of the roads. Additionally, the KHCM's LOS of the other modes, except for the automobile, is not consistent with actual road conditions. The KHCM, therefore, needs to develop and introduce a multimodal LOS system in order to evaluate the service conditions more accurately. METHODS: As a preliminary step to the introduction of multimodal LOS research, in this study the current problem of the KHCM's LOS system through a close review and comparison with other HCMs (highway capacity manuals) was identified. Secondly, a field survey and investigation of the urban streets to apply the HCM's multimodal LOS system was conducted. Finally, a comparison analysis of the results of the HCM and KHCM LOS was performed. RESULTS: In the study, it was found that the results of the LOS for the automobile mode did not show a significant difference between the HCM and KHCM. However, the LOS of the bicycle and pedestrian mode tended to be worse in the multimodal LOS system, which results from considering the effects of the automobile mode. Moreover, it was found that many cases have the potential to improve the overall LOS conditions, while reducing the automobile capacity. CONCLUSIONS: With the introduction of the multimodal LOS system, road diet and complete streets can be easily applied to ans actual road improvement project. Ultimately, the multimodal LOS system should be introduced into the KHCM, which can then be applied to traffic impact studies and other road improvement projects for more accurate evaluations.

• Proceedings of the KOR-KST Conference
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• 2007.02a
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• pp.161-170
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• 2007

• International Journal of Highway Engineering
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• v.17 no.5
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• pp.123-133
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• 2015

PURPOSES : This study aimed to develop a new highway capacity estimation method and provide comparative results among traditional capacity estimation methods and the recommended values in the latest version of KHCM. METHODS : The limitations of the existing methods, such as inconsistency and underestimation of the capacity value, are summarized through an extensive literature review. To overcome these limitations, a new method is introduced by adopting a definition of capacity and traffic flow characteristics at or near breakdown points. This method can produce the capacity value by searching a point corresponding to the maximum traffic flow through analysis of gradient changes (point of inflection) of the traffic flow and speed distribution. Comparative results of capacity values from each method are also presented to validate the new method by using data collected from detectors on freeways. RESULTS: From the analysis results, it is shown that a consistent capacity value can be estimated by applying the new method. In addition, the resulting capacity values are 3%-4% higher than those recommended in KHCM. CONCLUSIONS : The capacity values listed in the current KHCM tend to produce underestimated results. The new method presented in this paper may be included in the future edition of KHCM.

• Journal of Korean Society of Transportation
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• v.16 no.4
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• pp.113-126
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• 1998

본 논문에서는 1992년 KHCM 작성시 이용된 양방향 2차선 도로 및 고속도로의 승용차 환산계수 산정방법론 및 자료를 연구하였다. 대형차가 2차선도로, 고속도로의 교통류에 미치는 영향은 각기 다르므로 1992년 KHCM 작성시 승용차 환산계수를 산정하는데 있어서 각 도로의 특성을 최대한 반영하기 위해 다양한 방법을 적용하였다. 양방향 2차선 도로의 평지의 서비스 수준 A에서는 Walder 방법, 서비스 수준 B, C, D에서는 지체시간 방법, 서비스 수준 E에서는 차두간격 방법, 구릉지, 산지 특정구배에서는 실측 자료 및 TWOPASKI Simulation에 의한 방법을 적용하였고, 고속도로의 평지에서는 차두간격 방법, 그릉지, 산지, 특정구배에서는 실측 자료 및 VEHEQ Simulation에 의한 방법을 적용하였다. 양방향 2차선 도로는 한 방향당 차선이 하나이므로 추월시 대형차의 영향이 고속도로보다 크기 때문에 각 서비스 수준별고 승용차 환산계수를 제시했으며, 고속도로의 승용차 환산계수는 용량에 가까운 상태에서의 승용차환산계수를 제시하였다. 본 논문은 1992년 KHCM의 양방향 2차선 도로 및 고속도로의 승용차 환산계수 산정에 실지로 적용된 방법론 및 자료를 수정없이 그대로 제시하여 독자들이 승용차 환산계수 산정에 이용된 자료의 양 및 연구 수준의 정도를 이해할 수 있게 하고 독자의 평가를 통하여 미비한 부분은 추후 개정 작업에 반영하기 위함이다.

• Journal of Korean Society of Transportation
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• v.30 no.1
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• pp.75-83
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• 2012

This study is to find a shortcoming embedded in the current Korean Highway Capacity Manual (KHCM) on reflecting a heavy vehicle effect to the highway capacity. The KHCM suggests to handle the percent heavy vehicle to deal with its effect to a capacity regardless of density levels. Authors hypothesized in this study that the effect of heavy vehicles would vary at different levels of traffic density - the effect would be comparably insignificant when a density is low and it becomes comparably significant when it becomes high. Field data from a freeways located in Seoul were collected for 360 hours (15 days) and categorized them into a set of operation conditions grouped by 15 minutes and by the LOS density levels. Comparison between the field measured and the estimated by the KHCM method showed that the KHCM method overestimated the effect of heavy vehicles in LOS B and C but underestimated in LOS E. The results suggested that there be a difference pattern from the one the KHCM expected and brought discussion on further studies.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.1
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• pp.109-126
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• 2014

The level of service (LOS) of the Highway Capacity Manual (KHCM) has been used as a basic criterion at decision making processes for signalized intersections in Korea. The KHCM provides five steps for the signalized intersection analysis. Among them, lane grouping, which is the third step, significantly influence the final LOS. The current method presented in the KHCM, however, classifies a shared lane as a de facto turning lane group, even though the turning traffic of the shared lane is few. Thus, this research was initiated to provide an alternative. To this end, three alternatives were suggested, including the method based on the lane grouping presented in the U.S. Highway Capacity Manual, the method using turning ratio of shared turning lane, and the method using a threshold traffic volume in lane grouping. The feasibilities of the three methods were evaluated using a calibrated CORSIM model. Conclusively, the method using a threshold traffic volume in lane grouping outperformed.

• Journal of Korean Society of Transportation
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• v.22 no.4 s.75
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• pp.43-56
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• 2004

The KHCM procedure is a micro level analysis at signalized intersections requiring a lot of input variables and complex computations. The research was to investigate the possibility of simplifying the analysis procedures by using the generalized or the combined variables that less influence on the adjusted traffic volume and through-car equivalents of left or right turns. It was also tried to make lane grouping into directional flow ratio(v/s) based on a field surveys. The maximum and minimum values of each variables were compared with each other through the KHCM analysis procedures in terms of control delay. The lane grouping and the synthetical influence of a simplified method was evaluated with the scenario built in prevailing maximum and minimum conditions. The study showed that the control delay was not significantly sensitive to the selected variables and the lane grouping and their synthetical influence as well.

• Journal of Korean Society of Transportation
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• v.30 no.3
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• pp.7-15
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• 2012

Korean Highway Capacity Manual (KHCM) has been used when we analyze the pedestrian Level of Service (LOS) of a pedestrian facility. However, the pedestrian LOS by KHCM is largely insensitive to pedestrian congestion levels. The objective of this study is to identify the source of this problem within the KHCM calculation method, and to propose an improved method using the case study from Seoul. Based on KHCM results, the pedestrian LOS is A for more than 90% of the Seoul region, which seems to be unrealistic. On the other hand, this study includes an effective adjustment parameter using the absolute value of effective sidewalk width. Using this method, results shows some changes including newly identified areas of LOS C and LOS D. The analysis of pedestrian LOS is carried out for the entire metropolitan region of Seoul in order to evaluate area wide pedestrian level of service in Seoul.