통행시간 신뢰성 가치에 관한 연구

조한선 한국도로학회 2013 한국도로학회논문집 Vol.15 No.4

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.

통행시간예산의 지역적 특성 분석 연구

나승원,여옥경 국토지리학회 2011 국토지리학회지 Vol.45 No.4

Consistent transportation investment for the reduction of travel time is in the situation to bring about the result of the increase of traffic distance rather than reduction of traffic time. In this connection, this study examined the theory of travel time budget that claims the daily travel time use of travelers shows regularity at some extent in the aspect of time and space and analyzed what characteristics the regularity of travel time in the aggregate level shown in the studies on the travel time budget shows regionally. For this, using the data of ? “002, 2006 Seoul Metropolitan Area Travel Survey?”, it gained the result from the analysis of the daily travel time, distance, frequency changes of travelers by residing region that the travel distance relatively increased very much compared to the comparatively regular travel time and in particular, the increase of the Gyeonggi region became conspicuous. This is shown more clearly in the region of the influencing area of the metropolitan ring expressway that showed the reduction of travel time was used to longer travel distance due to the travel speed improvement for travelers. It was confirmed that travelers travel more and long distances rather than reduce the total travel time in order to maximize individual efficacy which was proved even in the metropolitan area. Due to the expansion of traffic facilities, accessibility improvement brought about the suburb expansion of the metropolitan population and it confirmed the increase of traffic distance. 통행시간 단축을 위한 지속적 교통기반시설투자는 통행자의 통행시간 단축보다는 통행거리를 늘리는 결과를 가져오고 있는 실정이다. 이에 본 연구에서는 통행자의 일일 통행시간사용이 시공간적으로 어느 정도 일정성을 보인다는 통행시간예산이론을 검토하여, 통행시간예산의 연구들에서 드러나는 집계적 수준에서의 통행시간의 일정성이 지역별로는 어떠한 통행특성을 나타내는지를 분석하였다. 이를 위하여 「2002·2006 수도권가구통행실태조사」 자료를 이용하여 수도권의 거주지역별 통행자의 일일 통행시간, 거리, 횟수 변화를 분석한 결과 통행시간은 비교적 일정한데 비해 통행거리는 상대적으로 많이 증가하였으며, 특히 경기지역의 증가가 두드러졌다. 이는 수도권 외곽고속도로 영향권의 지역에서 더 확연히 나타나는데, 이는 통행자들이 통행속도 향상으로 인한 통행시간 단축을 더 많은 통행에 사용한다는 것을 보여주는 것이다. 통행자들은 개인의 효용을 극대화하기 위하여 총 통행시간을 줄이기보다는 더 많은 통행이나, 더 긴 통행을 하는데 수도권에서도 이를 확인할 수 있었다. 교통시설의 확충으로 인한 접근성 향상은 수도권 인구의 외연확산을 가져오며, 이로 인한 통행거리의 증가가 확인되었다.

New methodologies for predicting corridor travel time mean and reliability

Zifeng Wu,Laurence R. Rilett,Weijun Ren 서울시립대학교 도시과학연구원 2022 도시과학국제저널 Vol.26 No.3

Accurate travel time prediction is very important for real-time traveller information systems. Many existing traveller information systems provide point estimates of forecast travel times. Often the forecast corridor travel time is estimated as a direct summation of the forecast link travel times on the route. This approach neglects the correlation between link travel times and may lead to inaccurate route travel time forecasts. This paper improves upon the simple addition method by accounting for the dependency of link travel times on the arrival time at that specific link which further correlates to its preceding links. In addition, this paper also explores the potential of using the nonlinear autoregressive with exogenous inputs (NARX) model and feedforward neural network model to forecast the corridor travel time mean and reliability metrics. To the authors knowledge this is the first time, short-term travel time reliability is measured by a reliability interval which is based on the forecasts of corridor travel time mean and standard deviation. The prediction methodologies developed in this paper are tested on an urban arterial that has been instrumented with Bluetooth readers so empirical travel times are available. It was found that the proposed NARX model outperforms the other models that were studied with respect to mean corridor travel time prediction. In terms of the reliability interval prediction, the performance of various models is presented as a Pareto Optimal Frontier trading off accuracy and usability. The proposed NARX model and three other tested models are all on the Pareto Optimal Frontier.

Estimating route travel time reliability from simultaneously collected link and route vehicle probe data and roadway sensor data

William L. Eisele,Bhaven Naik,Laurence R. Rilett 서울시립대학교 도시과학연구원 2015 도시과학국제저널 Vol.19 No.3

Route travel time variability estimates provide performance information related to the reliability of a trip and allow for confidence bands to be placed around the mean travel time estimates. The naïve (and sometimes used) method to estimate route travel time variance (reliability) is to assume independence of link travel times and consequently sum the individual link variances along the route. In this approach, correlation between links is assumed as zero and the approach is straightforward, but assuming independence is not realistic. This paper describes a post-processing procedure for providing improved route travel time mean and variance estimates, while taking into consideration the correlation existent between individual link travel times. Using automatic vehicle identification (AVI) and inductance loop detector (ILD) data from two separate routes in Texas, a practical application of the theory established by Fu and Rilett (1998. Expected shortest paths in dynamic and stochastic traffic networks. Transportation Research Part B: Methodological, 32(7), 499–516) is used to quantify link travel time correlation. The paper also provides an investigation on the usefulness of the loess statistical method and a polynomial regression model to estimate the distributional properties of link and route travel times. Another significant finding is that route reliability estimated from link ILD speeds (extrapolated to travel times) was not correlated to actual route travel time reliability measured by simultaneously operated probe vehicles. This work is unique in that instrumented probe vehicles were operated at exactly the same times as the roadway sensor data were collected, allowing direct comparison of the travel time estimates from all empirical data sources. The research presents valuable insight on how confidence intervals may be placed on travel time mean estimates for all traffic conditions. With the increased use of travel time data sources such as smartphones, connected vehicles, and private-sector data sources, the methods presented in this paper are invaluable for effective transportation system performance monitoring of both persons and freight movement.

Estimating freeway route travel time reliability from data on component links and associated cost implications

Kartikeya Jha,John P. Wikander,William L. Eisele,Mark W. Burris,David L. Schrank 서울시립대학교 도시과학연구원 2018 도시과학국제저널 Vol.22 No.3

Typically, data on travel time (speed) and traffic volume are collected for relatively short homogenous links of a roadway (e.g. every ½ to 2 miles or 0.8–3.2 km) and not for particular routes from origins to destinations. To accurately estimate a traveller’s trip, there is a need to build information on an entire route from data collected at the link level. Because it can be resource-intensive to define specific routes for the entire network of interest, route reliability performance measures are sometimes estimated using a vehicle-miles of travel (VMT)-weighted average of performance indices from links. In performance measurement, travel time index (TTI) is the ratio of average travel time and free-flow travel time while planning time index (PTI) is the ratio of 95th percentile travel time and free-flow travel time. TTI is considered a mobility measure while PTI reflects system reliability. Using indices based on free-flow (uncongested) travel time, this study finds that the VMT-weighting of link indices to get the corresponding route index gives reasonable results for the travel time index (TTI). However, this approach overestimates the planning time index (PTI). This highlights the statistical insufficiency of estimating route PTI values from link PTI values weighted by VMT. It points to the subsequent need to incorporate factors for dispersion and skewness characteristics of travel time distributions on constituent links. This paper introduces a promising method to estimate freeway route reliability considering these dispersion and skewness properties. For statewide Virginia Interstates considered here, economic analyses based on the value of travel time demonstrate that incorrect travel time reliability estimates result in upwards of 200% higher user costs. Researchers anticipate that the information documented in this paper will be useful for those conducting performance monitoring activities to estimate route reliability with limited resources when only link data are available.

생활시간조사 자료를 활용한 통행시간예산 연구

장수은 한국교통연구원 2018 交通硏究 Vol.25 No.3

The hypothesis entitled “travel time budgets” represents that personal daily travel time expenditure is stable. This paper empirically explored the theory analyzing the Korean time use survey data. Five research questions were raised and examined. First, Korean travel time budgets were 100 and 110minutes for total people and travelers only, respectively. Second, the cross-sectional stability of travel time use was not confirmed while the time-series stability of the spending was verified. Third, there were little connections between travel time budgets and day-of-week variations of travel time use. Fourth, travel time budgets of trip purposes for commuting and business and those for social interaction and leisure were found. In contrast, travel time budgets of the other trip purposes could not be examined mainly because their travel times consumed were too short. Fifth, inter-group average travel time use was different while intra-group average travel time expenditure showed time-series stability. The concluding remarks stressed the need for theoretical structure that can address the hypothesis itself and also can reestablish the relationship between existing transport theory and the stability of travel time use. 사람들이 하루 24시간 중 이동에 사용하는 평균 통행시간이 일정하다는 학설이 있다. 이를 통행시간예산이라고 한다. 본 연구는 통계청의 생활시간조사 마이크로 자료를 분석하여 이 가설을 실증적으로 검증하였다. 본 연구의 분석결과를 정리하면 다음과 같다. 첫째, 우리나라 교통체계의 통행시간예산은 모집단을 전국민으로 설정했을 경우 약 100분, 모집단을 통행자 집단으로 국한했을 경우 약 110분으로 나타났다. 둘째, 통행시간의 시계열적 안정성과 달리 횡단면적 안정성은 확인할 수 없었다. 셋째, 통행시간예산과 요일 변동 사이에는 큰 연관이 없었다. 넷째, “출퇴근 및 업무”와 “교제 및 여가” 목적의 통행시간예산은 나타났으나 그 외 나머지 통행목적의 평균 통행시간은 절댓값이 작아 통행시간예산 여부를 판단할 수 없었다. 다섯째, 사회집단 간 평균 통행시간 사이에는 일정 부분 차이가 있었으나 각 집단별 평균 통행시간은 시계열적 안정성을 보였다. 향후 연구과제로는 통행시간예산을 설명할 수 있는 이론체계, 특히 이 가설과 통행행태 이론 등 기존 교통학 이론체계와의 관계정립 문제가 강조되었다.

TCS 링크통행시간을 이용한 고속도로 경로통행시간 추정

이현석,전경수 대한교통학회 2009 대한교통학회지 Vol.27 No.5

운전자가 원하는 통행시간 예측 정보를 제공하기 위해서는 이미 알고 있는 교통상황 하에서의 통행시간 추정이 선행되어야 한다. 그러나 현재 고속도로에 적용되고 있는 지점검지기에 의한 통행시간 추정 방법은 신뢰성 있는 통행시간을 산출하기에는 한계가 있다. 따라서 본 연구에서는 신뢰성 있는 예측정보를 제공하기 위한 기반 결과로서 고속도로 경로의 기·종점 영업소 간에서 실제 소요된 통행시간의 추정에 주안점을 두었다. 통행시간 추정시 교통정보의 활용도 측면에서 매우 유용하면서도 풍부한 고속도로 통행료 수납시스템 (Toll Collection System,TCS) 자료를 이용하였다. 경로통행시간 추정모형에서는 경로 내의 링크통행시간을 조합하여 고속도로의 경로통행시간을 추정하였다. TCS 자료가 결측 된 경우에는 통행시간의 증가패턴을 분석하여 선형보간법을 통해 이전주기의 TCS 통행시간을 참조하였다. 결측이 장기간 지속되거나 통행시간의 변동이 심한 전이시간대에는 VDS 시공도에 의한 동적인 통행시간을 추정하였다. 본 연구에서 제안한 모형을 통해 추정된 경로의 통행시간은 경로를 직접 통행한 차량들의 통행시간과 통계적으로 차이가 없음이 검증되었다. 제안모형은 동일 출발 시간대에서는 통행시간의 편차가 심하고 전·후 시간대에서는 통행시간 대푯값의 변화 패턴이 불규칙한 장거리 구간에 대해 신뢰성 있는 통행시간을 추정할 수 있었다. 본 연구에서 추정된 통행시간은 교통 상황의 성능 지표 및 실시간 통행시간 예측 분야에 활용될 수 있을 것으로 기대된다. Travel time estimation under given traffic conditions is important for providing drivers with travel time prediction information. But the present expressway travel time estimation process cannot calculate a reliable travel time. The objective of this study is to estimate the path travel time spent in a through lane between origin tollgates and destination tollgates on an expressway as a prerequisite result to offer reliable prediction information. Useful and abundant toll collection system (TCS) data were used. When estimating the path travel time, the path travel time is estimated combining the link travel time obtained through a preprocessing process. In the case of a lack of TCS data, the TCS travel time for previous intervals is referenced using the linear interpolation method after analyzing the increase pattern for the travel time. When the TCS data are absent over a long-term period, the dynamic travel time using the VDS time space diagram is estimated. The travel time estimated by the model proposed can be validated statistically when compared to the travel time obtained from vehicles traveling the path directly. The results show that the proposed model can be utilized for estimating a reliable travel time for a long-distance path in which there are a variaty of travel times from the same departure time, the intervals are large and the change in the representative travel time is irregular for a short period.

통행시간예산의 특성 분석

추상호(Choo Sangho),나승원(Na Seung Won) 한국도시행정학회 2011 도시 행정 학보 Vol.24 No.2

It is important to identify travel behavior of individuals for the efficient transportation investment, and in particular the understanding of the pattern of travel time use has a great usefulness. Hereupon this study is to examine the travel time budget that has been discussed continuously, checking the regularity of travel time and analyzing characteristics at the aggregate level as shown in the previous studies of travel time budget. This study used the Seoul Metropolitan Area Travel Survey in 2002 and 2006, and thereby examined the changes of travel time budget for each individual and total travelers of the Seoul Metropolitan Area and analyzed for each socioeconomic index as the characteristic factor of travel time budget and analyzed the characteristics of travel time classified by travel purpose, mode, and regions. We confirmed that age, gender, income, employment status, ownership of vehicles are significant as the factors that explain daily travel time. It was identified that though individual travel time budget can show differences, the travel time budget classified by type and group at the aggregate level was somewhat constant. It was also found that the travelers tend to extend the distance and frequency of travel rather than diminish the travel time in order to maximize the utility.

통행목적을 고려한 통행시간 영향요인 분석

구자헌(KOO, Jahun),추상호(CHOO, Sangho) 대한교통학회 2021 대한교통학회지 Vol.39 No.5

하루는 24시간으로 제약되어 있으며, 사람들은 저마다 다양한 활동을 수행한다. 통행은 파생수요라는 특성이 존재하기 때문에, 통행시간 역시 다른 활동시간에 영향을 받는다. 이에 반해, 통행시간예산 이론에 따르면 하루 평균 통행시간은 비교적 일정한 것으로 나타난다. 종합해보면, 하루 전체 통행시간은 비교적 일정하며, 통행시간은 다양한 활동에 영향을 받는다는 결론을 도출할 수 있다. 이를 살펴보기 위해 본 연구에서는 목적별 통행시간의 상관성을 고려하여 활동시간에 따른 통행시간 변화를 살펴보고자 한다. 분석자료는 통계청에서 제공하는 2009년 및 2019년 생활시간 조사자료를 활용하였으며, 분석목적을 고려하여 전국 학령이상 인구 데이터를 활용하였다. 본 분석에 앞서 상관성 분석을 수행하였으며, 목적별 통행시간은 모두 상관성이 존재하는 것으로 나타났다. 따라서 오차항 간 상관성을 고려할 수 있는 겉보기 무관 회귀모형을 활용하였다. 분석 결과는 다음과 같다. 첫째, 인구밀도 및 도시비율변수는 모두 양의 영향력이 존재하는 것으로 나타났다. 둘째, 가구관련변수에 비해 개인관련변수에서 유의한 변수가 더 많은 것으로 나타났다. 셋째, 모든 목적통행에서 통행횟수 영향력이 점차 증가하는 것으로 분석되었다. A day consists of 24 hours, and people perform a variety of activities during the time period. Travel time is related to activities, since travel is derived demand. According to the travel time budget theory, the average travel time appears to be constant over time. However, travel time by purpose affects each other given that the total travel time is constant. Therefore, this study aims to analyze factors to influence the changes of travel time by purpose considering their correlations. The data for this analysis come from the time use survey data of Statistics Korea in 2009 and 2019, focused on people over school age. Prior to modeling, we conducted a correlation analysis, resulting in significant correlations of all pairs of travel times by purpose. Accordingly, a seemingly unrelated regression model was developed. The results of the model are as follows. First, it was found that both population density and urban ratio had positive influences on travel time. Second, the individual variables are more significant than the household variables in the model. Third, the effect of the number of trips on travel time by purpose gradually increased over time. These results can be useful for establishing transport policy strategies related to travel time.

Real-Time Traffic Information Provision Using Individual Probe and Five-Minute Aggregated Data

장진환 한국ITS학회 2019 한국ITS학회논문지 Vol.18 No.1

Probe-based systems have been gaining popularity in advanced traveler information systems. However, the high possibility of providing inaccurate travel-time information due to the inherent time-lag phenomenon is still an important issue to be resolved. To mitigate the time-lag problem, different prediction techniques have been applied, but the techniques are generally regarded as less effective for travel times with high variability. For this reason, current 5-min aggregated data have been commonly used for real-time travel-time provision on highways with high travel-time fluctuation. However, the 5-min aggregation interval itself can further increase the time-lags in the real-time travel-time information equivalent to 5 minutes. In this study, a new scheme that uses both individual probe and 5-min aggregated travel times is suggested to provide reliable real-time travel-time information. The scheme utilizes individual probe data under congested conditions and 5-min aggregated data under uncongested conditions, respectively. As a result of an evaluation with field data, the proposed scheme showed the best performance, with a maximum reduction in travel-time error of 18%.