PURPOSES : This study aims to calculate the estimation of travel time saving benefits from smart expressway construction by considering the willingness to pay for automated vehicles. METHODS : In this study, data were collected from 809 individual drivers through a stated preference survey. A multinomial logit model was constructed to analyze the choice behavior between arterial roads, expressways, and smart expressways. Through this, the values of time and benefits were estimated. RESULTS : The value of time was calculated at 19,379 won per vehicle per hour for arterial roads and expressways and 23,061 won per vehicle per hour for smart expressways. Applying these values to the Jungbu Naeryuk expressway, we evaluated the demand change and benefits resulting from the improvement to the smart expressways. The results show that the traffic volume on the Jungbu Naeryuk expressway is expected to increase by 4.7% to 20.7% depending on the changes in capacity. CONCLUSIONS : The travel time saving benefits are estimated as positive, resulting from the construction of smart expressways. The benefits resulting from the construction of new smart expressways are expected to be enhanced due to the anticipation of more significant time-saving effects.
PURPOSES : This study defines travel time reliability as a concept that explains the change in travel time that passengers can hardly predict and calculates the value of travel time reliability based on travel objectives.
METHODS : Because the reliability of passage time is difficult to estimate from actual passenger data, standard quantification measures have not been established despite various interests. In this study, the reliability of transit time was defined as the expense that passengers did not recognize in advance, such as an accidental delay caused by unforeseen circumstances. For analysis based on the individual behavior of users, the data were constructed using the optional experiment method (marginal rate of substitution method) of the stated preference survey, which has the advantage of controlling the correlation between attribute variables and maintaining the independence of the data of the study.
RESULTS : Consequently, the reliability value of travel time in mandatory-purposed traffic was almost identical to the value of travel time, and the reliability value of travel time in return and shopping/leisure, which is not mandatory during non-business-purpose traffic, is lower than the value of travel time. Comparing and analyzing with existing studies on estimating the reliability value of transit time, both work/ non-work purposes are in line with the overall research results. CONCLUSIONS : Estimating the reliability value of transit time for each purpose of passage was the first attempt, and it is meaningful to suggest a direction for quantifying and applying the reliability value of transit time along with the passage time value of this study.
본 연구에서는 통행시간 정보를 이용한 COSMOS의 실시간 신호제어 수정알고리즘을 제시하였다. 도시 교통정보시스템 UTIS과 같은 교통정보시스템의 통행시간 정보를 신호제어에 적용하였으며, 결정적 지체 모형을 이용해 통행시간으로부터 대기행렬과 포화도를 산정하기 위한 모형을 정립하였다. 또한 루프검지 기에서 수집되는 포화도와 통행시간으로부터 추정한 포화도를 융합해 COSMOS의 신호시간 산정과정에 적용하였다. 실시간 신호제어 수정알고리즘의 효과평가를 위해 VISSIM과 API 도구인 ComInterface를 이용한 미시적 시뮬레이션 분석을 시행하였으며, 과포화 상태 및 검지기 고장상황에 대한 효과적 대응이 가능함을 확인하였다. 최근 국내 교통관리분야에서는 도시교통정보시스템 UTIS, 첨단교통관리시스템 ATMS와 같아 구간통행시간을 수집할 수 있는 검지체계가 급격히 확산되고 있으며, 본 연구에서는 교통 신호운영 분야에서 교통정보시스템을 적용하였다는데 의의가 있겠다.
PURPOSES : The travel times of expressway buses have been estimated using the travel time data between entrance tollgates and exit tollgates, which are produced by the Toll Collections System (TCS). However, the travel time data from TCS has a few critical problems. For example, the travel time data include the travel times of trucks as well as those of buses. Therefore, the travel time estimation of expressway buses using TCS data may be implicitly and explicitly incorrect. The goal of this study is to improve the accuracy of the expressway bus travel time estimation using DSRC-based travel time by identifying the appropriate analysis period of input data. METHODS : All expressway buses are equipped with the Hi-Pass transponders so that the travel times of only expressway buses can be extracted now using DSRC. Thus, this study analyzed the operational characteristics as well as travel time patterns of the expressway buses operating between Seoul and Dajeon. And then, this study determined the most appropriate analysis period of input data for the expressway bus travel time estimation model in order to improve the accuracy of the model. RESULTS: As a result of feasibility analysis according to the analysis period, overall MAPE values were found to be similar. However, the MAPE values of the cases using similar volume patterns outperformed other cases. CONCLUSIONS: The best input period was that of the case which uses the travel time pattern of the days whose total expressway traffic volumes are similar to that of one day before the day during which the travel times of expressway buses must be estimated.
이용자는 해당 도로를 이용함으로써 얼마나 빠르게 이동을 할 수 있는가에 따라 경로를 선택하지만, 예 측가능한 통행시간을 얼마나 확보할 수 있는가에 대한 가치에도 큰 비중을 둘 수 밖에 없다. 현재 표준편 차(SD), 통행시간 불확실성(Rh), Buffer Time 등의 지표들이 널리 사용되고 있으나, 본 연구에서는 사회 과학 분야에서 널리 사용되고 있는,‘지니계수’(Gini coefficient)를 새로운 통행시간 신뢰도 평가 지표로 사용할 수 있는가를 증명해 보고자 한다. 지니계수는 이탈리아 통계·사회학자인 지니(Corrado Gini)가 1912년에 만든 것으로, 지수값은 0~1 사이로 나오는데 숫자가 작을수록 평등한 소득분배를 의미하고, 숫자가 1에 가까울수록 소득분배가 불평 등하다는 것을 의미한다. 통상적으로 0.4가 넘으면 소득분배의 불평등 정도가 심한 것으로 평가한다. 따 라서 본 연구에서 제안한 불평등지수(GI)는“해당 도로를 통행하는 이용자들의 통행시간에 대한 불평등 도”로 정의하고자 한다.
PURPOSES: This investigational survey is to observe a proper spatial aggregation method for path travel time estimation using the hi-pass DSRC system. METHODS: The links which connect the nodes of section detectors location are used for path travel time estimation traditionally. It makes some problem such as increasing accumulation errors and processing times. In this background, the new links composition methods for spatial aggregation are considered by using some types of nodes as IC, JC, RSE combination. Path travel times estimated by new aggregation methods are compared with PBM travel times by MAE, MAPE and statistical hypothesis tests. RESULTS : The results of minimum sample size and missing rate for 5 minutes aggregation interval are satisfied except for JC link path travel time in Seoul TG~Kuemho JC. Thus, it was additionally observed for minimum sample size satisfaction. In 15, 30 minutes and 1 hour aggregation intervals, all conditions are satisfied by the minimum sample size criteria. For accuracy test and statistical hypothesis test, it has been proved that RSE, Conzone, IC, JC links have equivalent errors and statistical characteristics. CONCLUSIONS : There are some errors between the PBM and the LBM methods that come from dropping vehicles by rest areas. Consequently, this survey result means each of links compositions are available for the estimation of path travel time when PBM vehicles are missed.
PURPOSES : Benefits for improvement of travel time reliability obtained from construction of new highways should be considered as a major factor in the feasibility study for highway constructions. The purpose of this study is to develop a method of estimation for the value of travel time reliability. METHODS : Highway type (urban/rural highway) and traffic flow type(interrupted/uninterrupted) was considered to estimate he value of travel time reliability. And Double-bounded Dichotomous Choice among Contingent Valuation Method(CVM) was applied to survey the willingness-to-pay of drivers when travel time reliability is improved. Finally the value of travel time reliability was estimated using the results of survey and logit model. The value of travel time reliability was estimated considering travel objectives, time constraint travel and non-time constraint travel. RESULTS: The value of travel time reliability of business trip is higher than that of non-business trip. The value of travel time reliability of time constraint travel is higher than that of non-time constraint travel. The value of travel time reliability in urban area is higher than that in rural area. CONCLUSIONS: It was concluded that the proposed method in this study is more realistic and proper to estimate the value of travel time reliability because it reflects the situations of time constraint travel and non-time constraint travel.
PURPOSES : The accuracy of travel time information is a key measure of effectiveness and reliability of advanced traveler information systems. This study aims at investigating drivers' perception on the acceptable level of information accuracy and their corresponding valuations. METHODS : A questionnaire survey was executed for collecting driver perception data to capture the expectation level of travel time information provided and their willingness to pay for the information. A Tobit model was adopted for exploring the relationship among the acceptable level, driver socioeconomic characteristics and travel attributes. Since drivers' willingness to pay for accurate travel time information can be different according to their travel lengths, a piecewise linear regression model was developed to capture the sensitivity of values of travel time information to travel length. RESULTS : The analysis results suggest that trip purpose and travel time are two dominant factors to determine drivers' acceptable level of travel time information. For business and short trips, drivers want more accurate information than for non-business and long trips. Drivers' willingness to pay for travel time information also varies depending on their incomes, trip purposes and travel lengths. The results also show that drivers' valuation of travel time information provided is sensitive to their travel length. For longer trips, drivers are less sensitive to travel time information and then put less value on the information provided. CONCLUSIONS : Censored nonlinear regression models are developed to estimate drivers' acceptable accuracy for travel time information and their valuation using questionnaire survey data. The findings on drivers perception to the required accuracy of travel time information and their corresponding willingness to pay can be used in the design and deployment of advanced traveler information system to improve its effectiveness and usefulness through high compliance.
Vehicle routing problem is one of the traveling salesman problems with various conditions such as vehicle capacity limits, delivery time windows, as well as time dependent speeds in metropolitan area. In this research hourly vehicle moving speeds informat
본 연구에서는 운전자의 일관성 있는 교통 정보 학습과정을 기반으로 한 일별 동적 모형을 개발하였다. 개발된 모형은 교통 정보 서비스의 효과 분석이 가능한 형태의 체계를 갖추었다. 즉, 교통 시스템에는 교통 정보 서비스 업체(ISP, Information Service Provider)가 존재하며, ISP의 가입자는 과거 실시간 교통 정보를 제공받으며, 이를 바탕으로 경로를 선택한다. 반면, 교통 정보 미가입자는 개인의 경험 또는 친구, 교통방송 등을 통해서만 교통 정보를 학습하게 된다. 운전자의 경로 선택은 Boundedly-rational 모형으로 표현되었으며, 주어진 동적 통행 수요와 경로 선택에 따른 도로 교통망의 성능을 평가하기 위해 미시 교통 시뮬레이션 모형 (파라믹스)이 사용되었다. 개발된 모형은 실제 도로망에 적용되었으며, 도출된 결과는 개발된 모형의 수렴성과 일관성있는 교통 정보 학습 모형의 효과를 입증하였다.
This research is about developing an efficient solution procedure for the vehicle routing problem under varying vehicle moving speeds for hour-based time interval. Different moving speeds for every hour is too difficult condition to solve for this type of
사회 경제적 변화에 따라 통행자 패턴은 상당한 변화를 가져왔다. 통행자 패턴 중 통행시간은 통행자에게 제한된 자원에 해당한다. 통행자들은 이 제한된 자원을 자신의 활동에 적절히 투입하여 효용을 극대화 하려고 한다. 즉 통행에 대해서 지불 할 수 있는 혹은 개인의 효용극대화를 위해 선택할 수 있는 고유의 통행시간예산을 가지고 통행한다. 본 연구는"2002년 가구통행실태조사"에서 수집된 통행자 특성 변수들을 토대로 상호관련성 및 특성분류가 가능한 CART 분석방법을 이용하여 통행시간예산에 영향을 미치는 특정 요인에 대한 그룹화 및 추출화를 수행하며, 그에 따른 통행자 통행시간예산 추정 모형을 도출하고자 하였다. CART 분석 결과, 통행시간예산에 영향을 미치는 요인으로는 나이, 주택규모, 주택종류, 고용형태, 직업, 세대주 관계 등으로 나타났고, 도출된 영향요인들의 특성을 고려하여 추정모형을 개발하였으며, 그 결과 나이, 주택규모, 주택종류가 전반적으로 양(+)의 영향을 미치는 것으로 나타났다, 고용형태에서 상대적으로 통행의 빈도가 낮은 재택근무가 음(-)의 값으로 나타났다. 특히, 직업의 경우 주부 무직 미취학아동과 농업 어업 수산업에 종사하는 사람이 음(-)의 값을, 행정 사무 관리직이 양(+)의 값을 가지는 것으로 나타났다.
최근 들어 널리 확대되는 ITS시설과 장비의 효율적인 활용을 위해서는 실시간 통행시간예측과 같은 핵심기술의 개발이 매우 중요하다. 실시간 통행시간 예측기술을 통해 도로 이용자에게 통행시간 정보를 제공해줌으로써 운전자가 정보에 기반을 둔 선택을 할 수 있게 되며, 이에 따라 도로이용자의 통행 효용 및 도로시설 이용효율을 극대화할 수 있다. 본 연구에서는 자료 성질이 다른 VDS정보와 AVI정보를 하나의 틀 안에서 융합하는 모형을 제시하였으며, 이를 통해 VDS정보의 실시간성과 AVI 정보의 현실반영 특성을 반영한 통행시간추정이 가능하게 되었다. 또한 실시간 교통정보 제공을 위해 알고리즘의 수치연산 처리량이 실시간 현장 적용이 가능한 수준이 되도록 모형을 개발하였다. 본 연구에서 제시된 통행시간 추정 모형의 적용가능성과 신뢰성은 실제 국도 교통량자료를 이용하여 검증하였다. 실험결과에 따르면 본 모형은 연산처리 효율성이 매우 우수하여 실시간 운영 이 가능할 뿐만 아니라 실시간으로 수집되는 검지정 보를 사용함으로써 예측의 정확도를 향상시켰다. 특히 본 연구에서 제시한 이질적 자료의 융합방법은 향후 새로운 형태의 검지자료를 활용하는데 있어서 매우 유용하게 사용될 수 있을 것으로 기대된다.