• Journal of Korean Society of Transportation
• /
• v.35 no.6
• /
• pp.511-524
• /
• 2017

This study aims to evaluate the availability of ABM (Active-Based Model), FEATHERS, as a policy evaluation tool. To achieve the goal, scenario analysis on flexible working policy was conducted to measure its impact on activity-travel behavior. As a consequence, there seems no significant change in worker's daily life, other than mitigating traffic congestion due to decreasing commuting travel in the rush hour. The result of VKT (vehicle kilometers traveled) shows an opposite pattern according to given household/individual constraints. The scenario analysis on telecommuting indicates a decreasing trend in both travel frequency and distance because of the diminished number of commuting trips. As the activity space of telecommuters is shifted to a residential area, there are more short-distance trips by using non-motorized transport, which leads to decrease in VKT (using a private vehicle). Thus, the sensitivity of VKT by population groups varies due to transport mode shift (between personal and another mode) and growing non-work trips (using a private mode). This study found few things. First, it is necessary to evaluate the details of policy impact by population groups since it can be varied depending on household/individual characteristics. Second, the case study shows a promising performance of ABM as policy measurement that provides reality in policy evaluation. Third, ABM allows us to do more accurate analysis (i.e. time-series analysis by population groups) of policy assessment than those of FSM (Four-Step Model). Lastly, a further effort in data collection, literature review, and expert survey should be made to enhance the accuracy and confidence of future research.

• Journal of Korean Society of Transportation
• /
• v.26 no.4
• /
• pp.251-264
• /
• 2008

One of the crucial elements to fully facilitate the various benefits of intelligent transportation systems (ITS) is to obtain more reliable traffic monitoring in real time. To date, point and section-based traffic measurements have been available through existing surveillance technologies, such as loops and automatic vehicle identification (AVI) systems. However, seamless and more reliable traffic data are required for more effective traffic information provision and operations. Technology advancements including vehicle tracking and wireless communication enable the acceleration of the availability of individual vehicle travel information. This study presents a UBIquitous PRObe vehicle Surveillance System (UBIPROSS) using vehicle-to-vehicle (V2V) wireless communications. Seamless vehicle travel information, including origin-destination information, speed, travel times, and other data, can be obtained by the proposed UBIPROSS. A set of parameters associated with functional requirements of the UBIPROSS, which include the market penetration rate (MPR) of equipped vehicles, V2V communication range, and travel time update interval, are investigated by a Monte Carlo simulation- (MCS) based evaluation framework. In addition, this paper describes prototypical implementation. Field test results and identified technical issues are also discussed. It is expected that the proposed system would be an invaluable precursor to develop a next-generation traffic surveillance system.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.15 no.3
• /
• pp.23-33
• /
• 2016

This study identified the factors that affect travel time budget by mode for traveler in Seoul using the SUR model. Individual, household and TAZ characteristics were selected as the explanatory variables. Transportation modes are summarized from 18 types to 6 types(walking, personal car, bus, subway, rail and bicycle). The results showed a distinct difference between personal transportation and public transportation. First of all, People who owned a car and driver's licence tend to prefer personal transportation. In addition, we can confirm the relationship between the bus and the subway which are most typical public transportation. Passengers who can available a personal mode preferred the subway than the bus. It is expected to suggest various implications related to the public transportation policy for Seoul metropolitan area.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.11 no.2
• /
• pp.57-66
• /
• 2012

This study intended to evaluate the operational performance change from the introduction of the bus signal priority system using the field data. To complete the objective, travel time and volume data were collected from the before and after study, then the distribution of individual vehicle's travel time and the difference of travel time and traffic volume were compared respectively. Analysis results showed that no significant volume change was observed from both passenger vehicle and bus for the major and cross streets. It was identified that the quality of travel time distributions of passenger vehicle and bus was improved after introducing the bus signal priority system. In terms of average speed, passenger car in a major direction increased by 6.5% and bus increased by 10.5% in general. Statistical tests showed that those speed differences were statistically significant at the 95% of confidence level. The results of this paper will be a good source for further research in the area of bus signal priority control.

• Journal of Korean Society of Transportation
• /
• v.21 no.4
• /
• pp.145-154
• /
• 2003

Multilevel and Multivariate Structural Equation Mpdel is applied to handle the hierarchical nature of the data and explain complex relationship among socioeconomic factors of individuals and household, activity participation, and travel behavior using Puset Sound Transportation Panel data. From analysis, variations of individual activity participation and travel behavior can be divided into two categories : Within-household variation and Between-households variation. Empirical results show that the interdependency index(p) of variables for household members within a household is between 0.13 and 0.33 indicating high interdependency. These results suggest that Multilevel and Multivariate SEM approach is an appropriate modeling methodology and gives additional information for activity participation and travel behavior. Also most of personal and household characteristics influence on activity participation and travel behavior within a household as well as between households.

• Journal of Korea Planning Association
• /
• v.54 no.6
• /
• pp.68-79
• /
• 2019

The purpose of this study is to propose a transit accessibility analysis method based on temporal variability of travel time. In this study, transit accessibility was defined in three levels (in transit route, spot and region unit) to present findings from different spatial scopes. Recently, Jeju special self-governing province reorganized bus system of the island. To compare transit accessibility before and after transit policy implementation, the reorganized bus system of Jeju special self-governing province was selected as a case study. This study used General Transit Feed Specification (GTFS) data format as storage public transit information, and calculated travel time using ArcGIS GTFS networks analysis tools. In the analysis of individual transit route level, we found the 3 types of accessibility changes which is increments, no significant changes and reductions and these results come from transit route change (number of transfer, distance change) rather than changes of vehicle interval. We found increases of inflow and outflow speed in most target spots and overall transit accessibility has been substantially improved in Jeju island. This study implies that accounting for temporal variability of travel time in accessibility analysis can result in more useful and sophisticated accessibility information in decision-making processes.

• Journal of the Korean Geographical Society
• /
• v.40 no.5 s.110
• /
• pp.514-532
• /
• 2005

The purpose of this study is to critically examine conventional spatial measures of individual accessibility, which are based on the notion of spatial proximity, the single reference location, and the unlinked travel model. Using space-time accessibility measures with the travel-activity diary data set of Portland Metro, US, three expectations from spatial measures on spatial patterns of individual accessibility were empirically examined: (1) does individual accessibility decrease with an increase of distance from the CBD?; (2) does the spatial pattern of accessibility resemble that of urban opportunity density pattern?; and (3) are spatial patterns of individual accessibility of different socio- demographic population groups basically similar as people in the same area share the same geographic characteristics regardless of gender, race, age, and so on? First of all, the results showed that spatial variations in individual accessibility were not directly determined by spatial proximity and opportunity density as suggested by previous accessibility measures. The spatial pattern of individual accessibility was dramatically different from that of urban opportunity density High peaks of accessibility level were found far away from the CBD and regional centers. This finding might be associated with the importance of multi-reference locations and linked travels in shaping accessibility in reality. Furthermore, this study found that spatial patterns of accessibility clearly differ between men and women. These findings suggest that access requires more than proximity, and that the interaction between person-specific space-time constraints and the consequential availability of urban opportunities in space-time renders different accessibility experiences to people even in the same region, which would be one of the key ingredients missing from conventional spatial measures of accessibility.

• Atmosphere
• /
• v.26 no.4
• /
• pp.565-576
• /
• 2016

The yellow dust events in Korea are often associated with extratropical cyclones (ETCs) that travel across the source regions of yellow dusts. Although such synoptic patterns are well documented, climatic features of ETCs themselves during the yellow dust events are not well understood. The present study reports climatic features of spring-time ETCs, which accompany the yellow dust events in Korea, by tracking individual ETCs with an automated tracking algorithm. By analyzing Lagrangian tracks of ETCs from 1979 to 2014, it is found that, during yellow dust events, ETCs are located around Vladivostok, Russia. They are typically originated from the leeside of Altai-Sayan mountains about three days before the onset of the yellow dust events, and travel either eastward or southeastward in time. While their tracks are not unusual, they grow faster over the source regions of the yellow dusts, possibly lifting desert dusts above the planetary boundary layer, and further develop slowly as they travel eastward.

• Journal of Korean Society of Transportation
• /
• v.17 no.5
• /
• pp.7-18
• /
• 1999

This Paper focuses on analyzing the influences of Teleservice on travel behavior and trip demand based on the individual behavior model. The first step is to classify individuals into different Person groups who will follow similar behavior Patterns in terms of travel and communication. And then, the effect of Teleservice on trip demand is estimated using hypothetical scenario. The results on the ability of each person group to adapt themselves to Teleservice show that full-time housekeepers and senior citizens are more likely to be alienated. It is also found that transition probability to Teleservice is high for activities in bank or public office where simple forms of information such as data or text are exchanged. On that basis, it is estimated that in Seoul the savings on trip demand by Teleservice will be 7.6% of total daily trip generations.

• Journal of Korea Multimedia Society
• /
• v.22 no.9
• /
• pp.1108-1121
• /
• 2019

As the quality and level of life rise, many people are doing search for various pieces of information about tourism. In addition, users prefer the search methods reflecting individual opinions such as SNS and blogs to the official websites of tourist destination. Many of previous studies focused on a recommendation system for tourist courses based on the GPS information and past travel records of users, but such a system was not capable of recommending the latest tourist trends. This study thus set out to collect and analyze the latest SNS data to recommend tourist destination of high interest among users. It also aimed to propose an altered TSP algorithm to recommend the optimal routes to the recommended destination within an area and a system to recommend the optimal tourist courses by applying the Elasticsearch engine. The altered TSP algorithm proposed in the study used the location information of users instead of Dijkstra's algorithm technique used in previous studies to select a certain tourist destination and allowed users to check the recommended courses for the entire tourist destination within an area, thus offering more diverse tourist destination recommendations than previous studies.