• Journal of the Korean Society of Safety
• /
• v.27 no.3
• /
• pp.153-160
• /
• 2012

Various social problems such as traffic congestion, car accidents and environmental problems(air pollution, noises etc.) have been happening in the Seoul metropolitan area that has the car oriented traffic system providing cars continuously. Along with this, the financial burden caused by current oil price anxiety made paradigm shift from caroriented to public transportation-oriented. Its typical example is an arterial branch bus system changing(bus lane through the center of main road) started in Seoul in July, 2004. But study on safety analysis of bus lane and characteristic of accidents are not sufficient enough to now. The bus lanes are expanded to provide roads for better traffic operation and accidents between buses and pedestrians or ordinary vehicles are considered main problems. This study divided each bus route of median bus lane(bus-only lane through the center of main roads) and bus lane at roadside by intersection and collected and analysed data about influence variables of bus accidents chosen in each section. We constructed a logistic model using collected data. As a result, bus lane at roadside are used by both buses and other kinds of vehicles differently from median bus lane and showed such characteristic in accident influence. Therefore access management to factors causing conflict and improvement of operation management are required. In case of median bus lane, the more buses moving general vehicle lane and traffic volume of section were, the more accidents happened. In case that stop line of center lane is not backward, view blocking of vehicles turning left caused accidents.

• International Journal of Highway Engineering
• /
• v.14 no.2
• /
• pp.145-155
• /
• 2012

At present, Seoul City is putting the bus exclusive lane system into practice according to mass transit revitalization policy. Starting with the installation of roadside bus exclusive lane in the past, at present, even the road sections for central- lane bus exclusive lane system are on the increase. The purpose of this research is to analyze the factors giving impacts on bus accident on central bus exclusive lane and roadside bus exclusive lane. In case of the central bus exclusive lane, the 6 variables, such as the number of bus routes, number of access & entrance to central lanes patterns, whether the stop line of central lanes retreats or not, separated distance between the stop line of central lanes and crosswalks, traffic volume, and number of bus routes stopping at bus stops on reversible lanes, were found to have a significant influence on bus accidents. In case of roadside bus exclusive lane sections, the four variables such as the number of right-turn bus routes, whether to be chronic illegal parking & stopping, time for the walk signal, and forms of land use, etc. were found to have a significant influence on bus accident.

• International Journal of Highway Engineering
• /
• v.15 no.6
• /
• pp.135-141
• /
• 2013

PURPOSES : The lack of details of design guideline for zig-zag shaped section approaching central bus stop leads an traffic accident proneness. So, this study analysed the geometric elements of central bus stop area in terms of vehicle dynamics and suggested design alternatives. METHODS : The study analysed a dynamic behaviour of bus moving in and out of zig-zag shaped section using Auto-Turn under scenarios. Based upon dynamic analysis, the study found out the width of overtaking lane is the most influential factor for a safe moving at zig-zag alignment. RESULTS : The width of overtaking lane at design speed of 40, 50, and 60 km/h respectively was suggested given taper ratio of 1 to 10 required for Bus Rapid Transit (BRT), and the lane width is not wider than 4.0m which possibly makes two vehicles using the same lane. Also, the width of overtaking lane which mitigates the taper ratio was suggested with the same restriction about the maximum lane width. CONCLUSIONS : The results of the study can be used to prepare a design guideline on zig-zag shaped alignment of central bus exclusive lanes. The more stable moving is expected by applying the design alternatives suggested, therefore the lower rate of traffic crashes at the vicinity of central bus stops.

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

• Journal of Korean Society of Transportation
• /
• v.31 no.4
• /
• pp.18-31
• /
• 2013

The operational purpose of exclusive bus lanes is to ease traffic congestion through the increase of person-carrying capacity on arterial roads. It is necessary to study on the route suitability for exclusive bus lanes because their operation may worsen traffic congestion due to the misuse of general purpose lane for an exclusive bus lane. This research quantifies the route suitability for exclusive bus lanes in Kwangju-city utilizing 7 indexes such as bus traffic volume, number of bus routes, traffic volume per lane, number of lane, number of intersection, number of streets, rate of curvature for the exclusive bus lane, recognizing the problem that the current installation standard of exclusive bus lanes is only limited to the bus traffic volume and the number of bus passengers. In addition, this research analyzes the operational efficiency for exclusive bus lanes, which is currently operated and their optimal operation hours.

• Journal of Korean Society of Transportation
• /
• v.24 no.5 s.91
• /
• pp.123-133
• /
• 2006

Seoul and many large cities in Korea have implemented Median Exclusive Bus Lane(MEB). But exclusive bus lane in the middle of the road caused new contradictions between left turn movement and through bus movement and several signal operation techniques like 'left turn Protected' and 'overlap phase' couldn't be applied in intersections on MEB. We suggest 'Bus-only Signal for median lane technique as solution of these problems This study presents optimum signal time design process and detailed algorithms for intersections where bus-only signals are installed. As a test field. we took Yang-Je intersection where Median Exclusive Bus Lane go through. and have large gap in volume of left turn in main direction. And we verified that revised optimum signal time including overlap phase can reduce average delay time of vehicle through before and after simulation.

• Journal of Korean Society of Transportation
• /
• v.31 no.4
• /
• pp.32-46
• /
• 2013

Because of short length between interchanges, traffic congestion has been caused by a lot of short trip traffic in the urban section of interregional expressway. Also, in case of expressway with Bus Only Lane, bus causes dangerous situation by conflicting between vehicles and buses in order to access from Bus Only Lane to IC. Therefore, this study aims to propose Express Lane applied by Bus Only Lane as a new lane operation in order to efficiently operate and to analyze the effectiveness on constructing Express Lane to the Pangyo-Hannam section in Gyeongbu Expressway. The study analyzes effectiveness by scenario using the micro traffic simulation tool, VISSIM 5.4. For this, the indicators which evaluate construction effect of Express Lane, are used by average delay time, average speed and total travel time. The results of the study showed the best effectiveness when Express Lane installed one, and it represented an ideal traffic condition when long distance trip traffic of the whole traffic is 25% in the study section. Therefore, the construction of Express Lane using Bus Only Lane achieves positive effectiveness on safety and expense aspect as well as uncongested flow.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.3 no.2 s.5
• /
• pp.75-83
• /
• 2004

July 1, 2004 Seoul Metropolitan city is operating the Median Bus Lane System on Gangnam Main Street, Seongsan-Susaek-ro (Road) and Dobong- Mia-ro (Road) as one of the systematic reorganizations in public transportation. It has been assumed that there was an improvement in the speed of bus considering that the Median Bus Lane System practiced on Cheonho-daero (Main Street) since 1996 have had 35km/h on the average. If the Median Bus Lane goes into effect, there is a problem with the left turn on the crossroad. The buses go on the existing first lane so that the left fuming cars cannot help but turn left on the second lane. In case that the Median Bus Lane is put into practice, the left turn on the crossroad should not be allowed. However, if the left turn is not permitted on the crossroads in the aforementioned main streets, neighboring residents will complain about it and there will be some difficulties in finding other detour. On the premise that the prevalent left turn on the crossroads is allowed while the Median Bus Lane is being put into practice, this study suggests the separation of a stop line between buses and other vehicles as a way of fuming left in a safe manner and a way to calculate the appropriate distance.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.12 no.4
• /
• pp.87-94
• /
• 2013

This study estimated the changes in delays and speeds of vehicles in exclusive bus lane and road when the High Occupancy Vehicles(HOV) use the median bus lane. Synchro simulation tool was used to optimize the traffic signal time on the network and VISSIM was applied to simulate various scenarios. Here, drivers behavior parameters in VISSIM was optimized using Simultaneous Perturbation Stochastic Approximation(SPSA) algorithm in order to represent real traffic condition. Based on the simulation results, the delay in Doan daero was decreased when the volume of HOV in current condition runs on the median bus lane, whereas delay in Doan dongro was increased in all scenarios. The changes in bus speed was not sharply decreased for both study sites, even though the number of HOV increased to 10%. Thus, it could be allowed that the HOV use the median bus lane in Doan dongro and Doan daero. Future research tasks include studying about changes in delay when the HOV use the curb bus lane.

• International Journal of Highway Engineering
• /
• v.16 no.4
• /
• pp.11-19
• /
• 2014

PURPOSES: This study is to suggest the improvement for bus rapid transit system in Seoul METHODS: The maintenance cost for bus lane damages and plastic deformations are increased by bus passing speed, heavy bus weight, and climate change (localized torrential downpour, subtropical climate) and the accident risk has been increased. RESULTS: Recent analysis of pavement damage indicates that bus lane damage caused by heavy weight is overwhelming and it is urgent to prepare countermeasures. CONCLUSIONS : Pavement data of bus rapid transit system, bus transit numbers and pavement damage elements were analyzed. By analyzing pavement maintenance, design and construction, the countermeasures for the improvement of bus lane pavement and effective maintenance were suggested.