• International Journal of Highway Engineering
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• v.14 no.6
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• pp.131-138
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• 2012

PURPOSES : Two-lane highways have one lane in each direction, and lane changing and passing maneuvers take place in the opposing lane depending on the availability of passing sight distance. 2001 Korea Highway Capacity Manual (KHCM) is classified into two classes of two-lane highways (Type I, II), and average travel speed and time-delayed rate are used as measures of effectiveness (MOEs). However, since existing two-lane highways have both uninterrupted and interrupted traffic flow-system elements, a variety of free-flow speeds exhibits in two-lane highways. In addition, it is necessary to check if the linear-relationship between volumes and time-delayed rate is appropriate. Then, this study is to reestablish the relationship between average travel speed, time-delayed rate, and flow. METHODS : TWOPAS model was selected to conduct this study, and the free-flow speeds of passenger cars and the percentage of following vehicles observed in two-lane highways were applied to the model as the input. The revised relationships were developed from the computer simulation. RESULTS : In the revised average travel speed vs. flow relationship, the free-flow speed of 90km/h and 70km/h were added. It shows that the relationship between time delayed-rate and flow appeared to be appropriate with the log-function form and that there was no difference in time-delayed rate between the free flow speeds. In addition to revise the relationships, the speed prediction model and the time-delayed rate prediction model were also developed. CONCLUSIONS : The revised relationships between average travel speed, time-delayed rate, and flow would be useful in estimating the Level of Service(LOS) of a two-lane highway.

• International Journal of Highway Engineering
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• v.15 no.5
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• pp.135-144
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• 2013

PURPOSES : The purpose of this paper is to develop a methodology to estimate level of service of arterial including Exclusive Median Bus Lanes. METHODS : On 6 Exclusive Median Bus Lanes routes in Seoul, bus travel time and number of bus-stop per km were investigated. Also whether or not passing lane exists at bus-stop was checked. Based on the data from sites, bus travel time was estimated according to length of segment, number of bus-stop per km and whether or not passing lane exists at bus-stop. RESULTS : A bus travel time table was developed according to length of segment, number of bus-stop per km and whether or not passing lane exists at bus-stop. After bus travel speed and passenger car travel speed is estimated based on each travel time table and length of segment, two speeds are combined with weighted average speed using traffic volume of each lane group. Then weighted average speed is a measure of effectiveness of arterial including Exclusive Median Bus Lanes. CONCLUSIONS : It can be concluded that the proposed methodology can estimate level of service of arterial including Exclusive Median Bus Lanes considering the operation characteristics of Exclusive Median Bus Lanes.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.245-249
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• 2004

This paper describes the vibration characteristics of Nd:YAG laser welding plates analyzed time-average Electronic Speckle Pattern Interferometry(ESPI). In laser welding, the travel speed has influence on a mechanical properties, such as elastic modules, response frequencies and so on, which is resulted on a residual stress of the welding zone. the response frequencies related to elastic modules are determined by time-average ESPI and the results, as compared to each condition, are used to estimate optimal condition of travel speed.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.465-473
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• 2005

In the analysis of the foreign cases on the use of Transit Signal Priority(TSP), the reduction in bus travel time ranged from 6 to $32\%$. This study demonstrates how TSP can be applied to Ulsan Metropolitan City. TSP techniques were used on the bus routes that run eastward for 4.07 kilometers along Munsoo-Ro, a major artery in the most congested part of the city. The simulation was performed on one hour of peak traffic time, using the two TSP strategies of Early Green and Extended Green. The use of the Early Green strategy resulted in an average decrease in travel time ranging from 18.1 to $25.8\%$ and an increase in average travel speed ranging from 30.9 to $40.1\%$. The Extended Green strategy resulted in an average decrease in travel time ranging from 18.1 to $30.3\%$ and an increase in an average travel speed of approximately $30.1\%$. This study demonstrates that TSP is effective in decreasing travel time and increasing travel speed of the bus system in Korea.

• International Journal of Highway Engineering
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• v.15 no.2
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• pp.159-167
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• 2013

PURPOSES : In this study, the effects of when median exclusive bus lanes were applied to Daejeon trunk road (Wolpyeng crossway~Seodaejeon crossway, 6.3km) and (Daeduck Bridge 4~Kyeryong 4, 2.6km) by Microscopic Simulation VISSIM (5.0) was studied. The median exclusive bus lanes are one of the measures of transportation system manage techniques that can especially improve the efficiency of public transportation facilities. METHODS : According to the analysis of VISSIM on the Gyerong mainroad and Daedeok mainroad, when the median exclusive bus lanes were applied unlike when the roadside bus-only lanes were applied, the average travel speed of vehicles decreased but the average delay time and travel time increased. This arised from the changes in the geometric structure of the road which occurred the reduction of vehicle lane in the center of the road. RESULTS : In the case of bus, on the other hand, the average travel speed increased but the average delay time and travel time decreased. This is because the problems such as illegal parking and stopping, secondary road in out vehicle, and conflict of intersection right turn that roadside bus-only lanes occurred was solved. CONCLUSIONS : Although the introduction of median exclusive bus lanes will have a negative effect on general traffic flow due to the aggravation of travel, decrease of passenger car usage will lead to decrease of traffic volume. Therefore, smooth vehicle travel is expected.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3D
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• pp.215-222
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• 2010

Average speed denotes a travel speed based on the average travel time of vehicles to traverse a segment of roadway, and average travel speed is used as a measure of effectiveness (MOE) suggested in the highway capacity manual (HCM) for evaluating the level of service (LOS) of roadway. Most of the urban freeways in our country are having congestion problem regardless of the rush hours as a high-speed highway with a speed limit of 80km/h or less. Especially traffic congestion within the ramp junction areas is becoming worse by the increased traffic and lack of links with the arterials around the urban freeway. So, the purpose in this study is to identify the traffic characteristics within the ramp junction areas of urban freeway, predict the average speed within the ramp junction areas based on the traffic characteristics identified, and finally prove the validity of the average speed predicted.

• Journal of Cadastre & Land InformatiX
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• v.51 no.1
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• pp.97-110
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• 2021

This study estimated the delay factor, which is the ratio of travel time at the speed limit and travel time at the actual speed using real-time traffic information in Seoul. The actual travel speed on the road was lower than the maximum speed of the road and the travel speed was the slowest during the rush hour. As a result of accessibility analysis based on travel speed during the rush hour, the travel time at the actual speed was 37.49 minutes on average. However, the travel time at the speed limit was 15.70 minutes on average. This result indicated that the travel time at the actual speed is 2.4 times longer than that at the speed limit. In addition, this study proposedly defined the delay factor as the ratio of accessibility by the speed limit and accessibility to actual travel speed. As a result of delay factor analysis, the delay factor of Seoul was 2.44. The results by the administrative district showed that the delay factor in the north part areas of the Han River is higher than her south part areas. Analysis results after applying the relationship between road density and traffic volume showed that as the traffic volume with road density increased, the delay factor decreased. These results indicated that it could not be said that heavy traffic caused longer travel time. Therefore, follow-up research is needed based on more detailed information such as road system shape, road width, and signal system for finding the exact cause of increased travel time.

• International Journal of Highway Engineering
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• v.18 no.3
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• pp.95-107
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• 2016

PURPOSES : This study compared two measures of traffic flow effectiveness on roads with roundabouts and signalized intersections and determined the more appropriate measure. METHODS : In addition to average delay time, the conventionally used measure, average travel time was introduced to measure traffic flow effectiveness because it is able to be obtained through field survey and reflect different travel distances and speed limits of roundabouts and signalized intersections. Using the two measures, roundabouts and signalized intersections were compared through simulations in terms of traffic flow effectiveness. RESULTS : For one-way single-lane roads, the two measures indicated consistent results that roundabouts were more effective than were signalized intersections when the traffic volume was less than 300 vphpl but vice versa when it exceeded 450 vphpl; however, the measures yielded inconsistent results when the volume was 350~400 vphpl. For one-way double-lane roads, the two measures indicated consistent results that roundabouts were more effective than were signalized intersections when the volume was less than 200 vphpl but vice versa when it exceeded 400 vphpl; however, the measures yielded inconsistent results when the volume was 250~350 vphpl. The results obtained using the two measures differed substantially for double-lane roads because behaviors such as weaving and lane changing at roundabouts are more common in double-lane roads than in single-lane roads. CONCLUSIONS : The average delay time would be lower on roads with roundabouts, but average travel time would be lower on roads with signalized intersections. Thus, evaluating the relative effectiveness of roads with roundabouts and signalized intersections by using average delay time alone would be inappropriate, whereas using average travel time as the evaluation index would yield fairer results.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.4
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• pp.1-10
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• 2013

This study was conducted to investigate that bus information was used as an information of travel speed. To determine the travel speed on the road, bus information and the information collected from the point detector and the interval detection installed were compared. If bus information has the function of traffic information detector, can provide the travel speed information to road users. To this end, the model of recognizing the traffic patterns is necessary. This study used simple moving-average method, simple exponential smoothing method, Double moving average method, Double exponential smoothing method, ARIMA(Autoregressive integrated moving average model) as the existing methods rather than new approach methods. This study suggested the possibility to replace bus information system into other information collection system.

• Journal of Industrial Convergence
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• v.18 no.3
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• pp.53-61
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• 2020

Travel speed is an important parameter for measuring road traffic and incident detection system. In this paper I suggests a model developed for estimating reliable and accurate average roadway link travel speeds using image processing sensor. This method extracts the vehicles from the video image from CCTV, tracks the moving vehicles using deep neural network, and extracts traffic information such as link travel speeds and volume. The algorithm estimates link travel speeds using a robust data-fusion procedure to provide accurate link travel speeds and traffic information to the public. In the field tests, the new model performed better than existing methods.