• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1D
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• pp.7-15
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• 2011

The travel time value is important factor for the evaluation of feasibility the transportation facility investment. The existing method for calculation of the travel time for each mode uses daily average trip purpose. So the value of travel time is constant because it is estimated with only daily average proportion. This daily constant time value can distort the results of future demands of toll roads or economic appraisals for the projects. The proportion of the trip purpose varies by time periods. Accordingly the value of travel time also varies by time periods. In this study, times periods are classified as morning peak, evening peak, business time off-peak, and non-business time off-peak. And trip purpose proportions are sorted by each time period from raw data of Seoul household trip study, then the value of travel time for each time period is estimated with these sorted purpose proportions. A case study of Seoul Jung-gu and Yongsan-gu performed with newly estimated time value by time periods. The result of benefit calculation with the daily constant time value is overestimated approximately annual 2.5 billion Won compared by time values by time periods. The demands of toll roads are also overestimated with the existing daily constant time value by daily 3,500 vehicles and total revenue of toll roads are overestimated by annually 1 billion Won. In conclusion, the value of travel time by each time period enables the more precise economic evaluation of the transportation facility investment projects, mode choice behavior, and route choice behavior especially for toll roads.

• Journal of Korean Society of Transportation
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• v.13 no.4
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• pp.5-29
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• 1995

Advanced Traveler Inoformation Systems*ATIS) , as a subsystem of ITS influence the travel choices of dreivers by providing them with historical, real-time and predictive information to supprot travel decisions and consequently improves the speed and quality of travel. For thesuccessul accomplishment of ATIS, the time-dependent variations of traffic in a road network and travel times of vehicles during their journey must be predicted . The purpose of this study is to evaluate the past developments in the dynamic route choice models and to apply the instantaneous dynamic user optimal route choice model. recently formulated with flow propagation constraints by Ran, Boyce and LeBlanc, to the real transportation network of Seocho-Ku in Seoul. As input data for this application, the time-dependent travel rates are estimated and the link travel time function is derived. The modelis validated from three view points : the efficiency of model itself the ability to predict traffic volume and travel time on links, and the optimal traffic control.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.559-564
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• 2006

The purpose of this study is to minimize negative effect of VMS travel time information service by sensitivity analysis, which forecasts the change in link traffic volume. As a result, strategies for providing travel information that can change driving patterns for minimizing travel time were found. The framework for analysis is recently expanded with the application of game theory. According to the experiment, the algorithm generated for travel time information service reduces total travel time and yields travel patterns that is very close to the system optimization. Also, this study found that the route the travel time service information is provided about could play the important role.

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.217-226
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• 2008

The term, travel-time reliability, refers to variations in journey time that travelers cannot predict. The purpose of this paper is to suggest a standard way to measure travel time reliability. A modified buffer time indicator is proposed. The index is represented by the difference between planned and actual travel times based on lognormal type travel time distribution. Using this framework, a constant function for railways and a negative parabola function for roads are discussed. The model developed is applied to the real data of Korean road and rail usages to empirically verify the methodology proposed. In this process, the unit value of travel time reliability for each group is estimated. The result of this research is expected to be helpful of conducting more cautious economic feasibility studies of transport.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.4
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• pp.62-72
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• 2015

Nowadays the issue of aging society has received considerable critical attention, especially in transportation planning and demand forecasting. This study identified the factors related to travel time budget for elderly by purpose using seemingly unrelated regression model (SUR model). The SUR model is suitable when error terms of each equation are assumed to be correlated across the equations in terms of travel time budget which is constant in 2 hours per day commonly. The results showed that elderly's travel time budget was affected by individual, household, urban facility and transportation service. The leisure travel comprised a large proportion of total travel time and had a positive relationship with elderly, sports, religious facilities. Moreover, the elderly who had low income or unemployed person had low frequency of social activity such as leisure, shopping and business. This study can provide a comprehensive implications of forecasting the future travel demand and analyzing the travel behavior.

• Journal of Korean Society of Transportation
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• v.30 no.6
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• pp.59-70
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• 2012

The relative importance of leisure trip has been increased after adopting the five-day workweek system and considering the higher income level. Thus, the value of travel time for intercity leisure trips should be estimated to conduct a reasonable benefit/cost analysis for railway construction projects. In this paper, the value of travel time was estimated separately for each trip purpose such as business, leisure, and other non-business than leisure. The estimated values of leisure travel time ranged from 5,310 to 14,185 (won/hr) by altering travel mode, and were increased by 42-107% when comparing with those of non-business travel time. Besides, how to apply the value of intercity leisure travel time for B/C analysis of railway projects was suggested. For the construction case of a railway connecting Chuncheon and Sokcho, the estimated benefit was increased by 2.3%.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5D
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• pp.739-746
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• 2006

The bus probe-based link travel times were more readily available due to bus' fixed route schedule and it was different from that of taxi-based one in its value for the same link. At the same time, the bus-based one showed less accurate information than the taxi-based link travel time, in terms of reliability expressed by 1-RMSE(%) measure. The purpose of this thesis is to develop a heuristic algorithm for mixing both sources-based link travel times. The algorithm used both real-time and historical profile travel times. Real-time source used 4 consecutive periods' average and historical source used average value of link travel time for various congestion levels. The algorithm was evaluated for Seoul urban arterial network 3 corridors and 20 links. The results based on the developed algorithm were superior than the mere fusion based link travel times and the reliability amounted up to 71.45%. Some limitation and future research agenda have also been discussed.

• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.97-108
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• 2008

Like always selecting anything in everyday lives, We must choose a travel mode to achieve its purposes driven by diverse factors such as travel distance and accessibility of public transit. Assuming that they are differentiated depending on whether a travel purpose is commuting, shopping or leasure, the study investigated their distinguished impacts on travel mode choice by using binary logit models by travel purpose and mode. Identifying that travel time has an important role in choosing a travel mode whether its purpose is any, the results show that longer travel time tends to increase the possibilities of taking public transit, transfer and rail transit rather than bus. In addition, the easy use of a car and its parking to travelers is more important in their choosing an automobile as a travel mode than other factors. In the models of identifying the probability of mode choice between bus and rail transit, we find that its choice tends to be decided by travelers depending on whether any public transit mode is more accessible to them. When comparing the results among travel purposes, we identify that the easy use of a car and parking in their destination is more important for commuting, while accessibility of public transit in their origination increases the probability of taking a transit mode.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.348-359
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• 2017

Recently, various public transportation activation policies are being implemented in order to mitigate traffic congestion in metropolitan areas. Especially in the metropolitan area, the bus information system has been introduced to provide information on the current location of the bus and the estimated arrival time. However, it is difficult to predict the travel time due to repetitive traffic congestion in buses passing through complex urban areas due to repetitive traffic congestion and bus bunching. The previous bus travel time study has difficulties in providing information on route travel time of bus users and information on long-term travel time due to short-term travel time prediction based on the data-driven method. In this study, the path based long-term bus travel time prediction methodology is studied. For this purpose, the training data is composed of 2015 bus travel information and the 2016 data are composed of verification data. We analyze bus travel information and factors affecting bus travel time were classified into departure time, day of week, and weather factors. These factors were used into clusters with similar patterns using self organizing map. Based on the derived clusters, the reference table for bus travel time by day and departure time for sunny and rainy days were constructed. The accuracy of bus travel time derived from this study was verified using the verification data. It is expected that the prediction algorithm of this paper could overcome the limitation of the existing intuitive and empirical approach, and it is possible to improve bus user satisfaction and to establish flexible public transportation policy by improving prediction accuracy.

• Journal of the Korean Society for Railway
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• v.11 no.4
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• pp.417-423
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• 2008

Transportation planners are increasingly adopting policies aimed at changing travel choices made by general commuter. Theories on the relationship between high-speed technology and transport address changes in travel behavior of regional commuter due to alterations in the Kyung-Bu railroad transportation corridor. The purpose of this paper is to examine the relationships between travel behavior and high-speed technology. The KORAIL data allows us to explore the differences between travel characteristics that are usually hard to discern by guesswork. The effects of travel time were found to be significant in the full decisions that control for commuting KTX. Although many argue that transportation behavior cannot be changed, this paper demonstrates that about 4 years of behavioral data on KTX travel show otherwise. In this paper we explore several possibilities to fill in some of the gaps in our knowledge on the expansion of commuter belt.