• Journal of the Korean Society for Railway
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• v.16 no.1
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• pp.59-64
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• 2013

This study analyzed passenger access and egress travel patterns related to a Korean regional railway station (Seoul station), then developed a binomial logit model. This model referred to bus and metro mode of access and egress during a national holiday (Chuseok 2009); obtained from transit smart card data. The results showed that 99% of passengers getting access to, or egress from, the regional railway station did so using less than two transfers, and that most passengers were more likely to choose a metro. However, the passengers that made access or egress trips near Seoul Station were more likely to take a bus. From the results of the mode choice model, it was found that the impact of travel time was greater than that of travel cost, in the choices made for both access and egress. Interestingly, the impact of travel time is much greater in choosing the mode of egress.

• Journal of Korean Society of Transportation
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• v.33 no.3
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• pp.268-275
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• 2015

As Korea is predicted to be a super-aged society in the near future, transport policies that internalize the elderly have also drawn attentions. Even though some studies have examined the travel by the elderly with various motives, it is, however, difficult to find references that deal with the unique spatio-temporal characteristics of senior trips. For example, the models by time period have represented the temporal property while a set of independent variables associated with urban infrastructure have addressed the spatial feature. This study was conducted under a trip attraction model for transit. The result shows that transit facilities, commercial areas, and hospitals are the dominant factors to explain the travel by the elderly, particularly during 09:00-17:00.

• Journal of Korean Society of Transportation
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• v.23 no.2
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• pp.143-150
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• 2005

Estimation of trip distribution, estimated O-D matrix must satisfy the condition that the sum of trips in a row should equal the trip production, and the sum of trips in a column should equal the trip attraction. In most cases the iterative calculation for convergence is needed to satisfy this condition. Most of all present convergence of iterative methods may results a big difference between estimated value and converged value, and from this, the trip distribution patterns may be changed. This paper presents a new convergence of iterative method that comes closer to meeting the convergence condition and gives the maximum likelihood estimation for calculating a distribution patterns from the trip distribution estimation model. The newly developed method differs from existing methods in three important ways. First, it simultaneously considers both the convergence condition and the distribution patterns. Second, it computers simultaneous convergence of rows and columns instead of iterating respectively. Third, instead of using the growth rates to the trip production, trip attraction, it uses the differences between trip production and sum of trips in a row, and trip attraction and sum of trips in a column. Using 38 by 38 O-D matrix, this paper compared the Fratar method and the Furness method to the newly developed method and found that this method was superior to the other two methods.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5D
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• pp.763-769
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• 2006

Gravity Model estimates target year's distributed trips using three variables like as origin zone's trip production, destination zone's trip attraction and traffic impedance between origin zone centroid and destination zone centroid. Estimating inner zone trip by gravity model is impossible because traffic impedance of inner zone has "0" value. So till today, for estimating inner zone trips, other methods like growth factor model are used. This study proposed inner zone trip estimation method that calculates inner zone's traffic impedance using established gravity model and estimates inner zone trips by putting calculated traffic impedance into the gravity model. 1988 year's surveyed O-D as basic year's O-D, proposed method's and existing methods(growth factor method and regression model)'s estimated results of 1992 year's and 2004 year's were compared with each year's real O-D by $x^2$, RMSE, Correlation coefficient. And resulted that the proposed method is superior than other existing methods.

• Journal of the Korean Geographical Society
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• v.42 no.6
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• pp.914-929
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• 2007

This study analyzes the accessibility patterns for commuting trips in Seoul Metropolitan Area using National Census Data between 1990 and 2000. the results show that the accessibility increased between 1990 and 1995, while it decreased between 1995 and 2000, due to the raised commuting time. Seoul, Kangju, Yeuju, Yangpyoung, Gapyoung show relatively high accessibility. The GINI parameters tell that the regional balance for commuting accessibility were worsen between 1990 and 1995, compared to that between 1995 and 2000. The accessibility patterns for commuting to Seoul were also analyzed and the result shows that the accessibility reduced between 1995 and 2000. Kwachun, Kwangju, Sungnum are found to have very high accessibility to Seoul, which is close to Soeoul with high percentage of incoming commuting trips. These results indicate that even continuous transport infrastructure supplies were not enough to solve the congestion problems for commuting trips in Seoul Metropolitan Area because of the induced traffic and traffic congestion.

• Journal of Korean Society of Transportation
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• v.28 no.6
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• pp.159-166
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• 2010

Trip distribution is to connect travel demand for each OD pair based on travel cost, trip production and attraction derived from trip generation step. In real world the travel cost is a function of travel demand, but existing models could not fully consider such functional relation between travel cost and demand, which leads to an equilibrium in trip distribution model. This paper proves the equilibrium trip distribution by using gravity model. In order to obtain such equilibrium this paper also presents a solution algorithm based on fixed point theorem. The algorithm will be tested with an example and confirmed the equilibrium solution of trip distribution.

• Journal of the Korean Geographical Society
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• v.44 no.3
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• pp.339-354
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• 2009

The purposes of this study are to identify many implications of commuting regional type according to the features of foreigner commuting. Research on the pattern of distribution of foreigners has been very simple and limited because foreigners usually lived together in a specific area, and their workplace often tended to be their residence. However they currently live dispersed more Widely, and their job and housing increasingly tend to be mismatched. This study divided areas inhabited by foreigners into general one characterized by job-housing match and exceptional one characterized by job-housing mismatch, and then examined the features of foreigner commuting. General commute type showed a high rate of intra area commute and foreign workers' universal features. Inflow commute type showing high E/R ratio. In these areas, outflow commuters had a short journey to work while inflow commuters had relatively a long journey to work, and professionals accounted for a high proportion of employees. Outflow commute type showing low E/R ratio. In these areas, outflow commuters had a long journey to work while inflow commuters had a relatively short journey to work. The composition ratio of three commute types was different according to nationality and visa type.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.93-100
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• 2010

Trip generation is the first step in the conventional four-step model and has great effects on overall demand forecasting, so accuracy really matters at this stage. A linear regression model is widely used as a current trip generation model for such plans as urban transportation and SOC facilities, assuming that the relationship between each socio-economic index and trip generation stays linear. But when rapid urban development or an urban planning structure has changed, socio-economic index data for trip estimation may be lacking to bring many errors in estimated trip. Hence, instead of assuming that a socio-economic index widely used for a general purpose, this study aims to develop a new trip generation model by type based on the market separation for the variables to reflect the characteristics of various zones. The study considered the various characteristics (land use, socio-economic) of zones to enhance the forecasting accuracy of a trip generation model, the first-step in forecasting transportation demands. For a market separation methodology to improve forecasting accuracy, data mining (CART) on the basis of trip generation was used along with a regression analysis. Findings of the study indicated as follows : First, the analysis of zone characteristics using the CART analysis showed that trip production was under the influence of socio-economic factors (men-women relative proportion, age group (22 to 29)), while trip attraction was affected by land use factors (the relative proportion of business facilities) and the socio-economic factor (the relative proportion of third industry workers). Second, model development by type showed as a result that trip generation coefficients revealed 0.977 to 0.987 (trip/person) for "production" 0.692 to 3.256 (trip/person) for "attraction", which brought the necessity for type classifications. Third, a measured verification was conducted, where "production" and "attraction" showed a higher suitability than the existing model. The trip generation model by type developed in this study, therefore, turned out to be superior to the existing one.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.11a
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• pp.599-617
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• 2006

A network model and a Genetic Algorithm(GA) is proposed to solve the simultaneous estimation of the trip distribution and traffic assignment from traffic counts in the congested networks in a logit-based Stochastic User Equilibrium (SUE). The model is formulated as a problem of minimizing the non-linear objective functions with the linear constraints. In the model, the flow-conservation constraints of the network are utilized to restrict the solution space and to force the link flows meet the traffic counts. The objective of the model is to minimize the discrepancies between the link flows satisfying the constraints of flow-conservation, trip production from origin, trip attraction to destination and traffic counts at observed links and the link flows estimated through the traffic assignment using the path flow estimator in the legit-based SUE. In the proposed GA, a chromosome is defined as a vector representing a set of Origin-Destination Matrix (ODM), link flows and travel-cost coefficient. Each chromosome is evaluated from the corresponding discrepancy, and the population of the chromosome is evolved by the concurrent simplex crossover and random mutation. To maintain the feasibility of solutions, a bounded vector shipment is applied during the crossover and mutation.

• Journal of Korean Society of Transportation
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• v.24 no.1 s.87
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• pp.7-18
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• 2006

Nowadays, the movement of commercial vehicles has caused severe congestion, environmental problems and damaged pavements in urban area. To solve the Problems, this research has proposed a methodology to build-up a freight network that is enable to manage the movement and demand of commercial vehicles. The network based on urban arterial network has developed according to freight traffic volume that is under the influence of road types among The in study area. Freight network has been developed by assignment method of 4-step transportation forecasting. Once, acceptable limits of freight traffic volume are decided, freight network can be developed using the capacity To confirm the application of the methodology, freight network of Seoul city has developed by the methodology.