Until the 1960s, buses played a central role in public transportation. Thereafter, however, this role gradually declined due to the increase of private cars resulting from continuous economic growth from the 1970s onwards and the development of other public transportation systems resulting from the expansion of urban areas. The rapid increase in private cars caused traffic congestion in large cities. Among the traffic system management techniques that were introduced to solve this problem, the exclusive median bus lane system reaffirmed the importance of the bus.

The Traffic System Management Act, which has been enforced since the early 1970s, was a short-term, low-investment method designed to curb traffic demand and optimize the use of existing traffic facilities, while the existing method was a long-term, high-investment method focused on increasing traffic facilities. The exclusive median bus lane system, as one of these traffic system management techniques, was expected to anticipate the transition from demand for private cars to that for buses through the improvement of bus services, in particular, as a method of simultaneously reducing the demand and supply of traffic.

Such a system offers the same transportation capacity as light rail transit but at a much lower investment cost than a subway system; moreover, it can be easily improved or restored during operations. Above all, it is effective in encouraging the conversion from private cars to buses.

In Seoul, a total of 218.5km exclusive bus lanes have been installed in 59 sections since the exclusive median bus lane system was first introduced by installing a roadside exclusive bus lane on Wangsan Road in 1986.

Full-time: 23 sections, 46.1km (07: 00-21: 00)

Part-time:18 sections, 44.6 km (07: 00-10: 00, 17: 00-21: 00)

Exclusive median lane: 12 corridors, 119.3km

The importance of the exclusive median bus lane policy was first emphasized from a theoretical perspective by traffic researchers from the US and the UK (Downs 1977; Mogridge and Williams 1985). In other words, according to the theory, if a road is expanded or newly established to mitigate traffic congestion, it will have a short-term effect on improving the travel speed first. However, the capacity of the expanded road will encourage new traffic and the congestion will increase again in the long term, whereas the policy that increases only the travel speed of public transportation can have a positive effect on relieving traffic congestion by increasing the travel speed of both public transport modes and private cars by attracting private car users to public transportation.

The establishment of exclusive median bus lanes in Seoul has made the most remarkable progress within the larger framework of the reform of public transport system, as is widely known. Therefore, it is closely related to major policy factors that constitute the public transportation system – such as the integration of bus service routes, the integration of fares, transfer centers, and traffic information integration and planning. In particular, the exclusive median bus lanes that were installed together with these means of 'integration' had a clearer effect than the previous roadside exclusive bus lanes - partly because of the physical difference between the median lane and the roadside bus lane. But this policy was related to a series of policies that enhanced the competitiveness of buses in general, in that a single policy that strengthens the competitiveness of buses when compared to cars has limited effects, and users are only able to perceive the effect when it is generated in combination with other policies. This policy is most closely and directly related to the policy measures that can shorten bus travel times.

The direct policy objective of exclusive median bus lanes is to shorten travel times. This is the ultimate goal of car users when switching from car to bus. However, bus travel times from a user’s point of view also include the time taken to get to a bus stop, the bus waiting time and the bus stop departure time, as well as the time actually spent on the bus. It may also include the time lost while the bus itself waits to comply with the bus timetable after boarding. In addition, exclusive median bus lanes (with the aim of maintaining relatively higher bus running speeds than those of other vehicles) are only effective in overcoming a drop in driving speed due to congestion; however, they cannot control other factors such as signaling systems and vehicle accidents. Therefore, this policy is closely related to the overall policy measures that can reduce the total travel time of buses, such as the integrated charge collection, in particular, electronic means of fare payment, service linkage with other public transport modes, bus stop connections, and the automation of public transport information, as well as having a close complementary relationship with a series of TSM (Transport System Management) factors such as signaling system synchronization, bus priority signal system, control and management of bus stops, and surveillance of illegal parking and illegal use of exclusive median bus lanes.

The main policy objectives of the exclusive median bus lane system are to secure lanes that can only be used by buses in regions where the average travel speed is habitually low due to traffic congestion, thereby allowing buses to maintain a superior travel speed to that of cars using the other lanes, and to actively encourage people who use cars to switch to buses.

The following conceptual flow chart clearly shows how the installation of exclusive median bus lanes can lead to the transition from cars to public transportation and contribute to improving the overall road conditions.

Figure 1. Improvement of Congestion by Introduction of Exclusive Median Bus Lanes

Source: Han, Sang-Jin (2007) Opinion

Figure 3: Installation Planning Map of Exclusive Median Bus Lanes by the Seoul Metropolitan Government and the Ministry of Land, Transport and Maritime Affairs, 2008

 

Figure 4: Installation Planning Map of Exclusive Median Bus Lanes by the Seoul Metropolitan Government and the Ministry of Land, Transport and Maritime Affairs, 2013

Source: Traffic Operation Information Service, 2013

For one-way three-lane roads:

• Roadside exclusive lanes considered when there is an excess of 60 cars per hour or more and 1,800 people per hour or more
• Roadside exclusive lanes considered or contra-flow exclusive lanes possible if there is an excess of 100 cars per hour or more and 3,000 people per hour or more
• Median exclusive lanes possible and overtaking lanes at the bus stops provided if there is an excess of 150 cars per hour or more and 4,500 people per hour or more

For one-way four-lane roads:

• Roadside exclusive lanes and overtaking lanes at the bus stops offered if there is an excess of 100 cars per hour or more and 3,000 persons per hour or more.
• It is possible to offer median lanes and overtaking lanes at bus stops when there is an excess of 150 cars per hour or more and 4,500 people per hour or more

Source: Traffic Operation Information Service, 2013

Source: Traffic Operation Information Service, 2013

Source: Traffic Operation Information Service, 2013

※ Average No. of daily passengers on five routes (701,703,704,706,720) from Gupabal to Seoul Station

Source: Traffic Operation Information Service, 2013

The total number of daily bus users in Seoul stood at 4.78 million in 2004 during the early stage of the introduction of the exclusive median bus lanes; however, this figure increased to approximately 5.8 million (average increase of 21% on a daily basis) in 2011. Therefore, the Seoul Metropolitan Government regards the establishment of exclusive median bus lanes as having been effective in invigorating the use of public transportation.

Transient Increase in Traffic Accidents

In the early days of the exclusive median bus lane system, traffic accidents tended to increase temporarily due to unauthorized crossing by pedestrians and public transportation users who had not yet adjusted to the newly changed traffic system and the improved speed of buses. However, the number of accidents has been decreasing every year along with the continuous expansion of exclusive median bus lanes as a result of rising public awareness and the establishment of an orderly traffic culture due to continuous promotion of the exclusive median bus lane system.

In addition, in order to reduce traffic accidents, the installation of safety barriers around the exclusive median stops and crosswalks, shock absorbers at road junctions, photovoltaic rechargeable raised pavement markers for lane guidance, and speeding prevention facilities at the stops was carried out along with regular safety education programs for bus transportation service workers.

Insufficient Capacity of Exclusive Median Bus Stops

For some bus stops and general traffic congestion points where build-up occurs due to the concentration of passengers getting on and off buses since the introduction of the exclusive median bus lanes, the Seoul Metropolitan Government will strive to resolve the inconvenience of bus users and drivers of general vehicles by executing projects to enhance the capacity of bus stops and traffic improvement projects to relieve traffic congestion. It will also continue to improve upon factors that inhibit traffic safety and obstacles to communication by observing the traffic situation on sections within the exclusive median bus lanes.

Measures for Overcoming Problems and Implementation Status

In the early days of the system, traffic accidents on the exclusive median bus lanes tended to increase temporarily due to unauthorized crossing by pedestrians and public transport users who had not yet adjusted to the newly changed traffic system and the improved speed of buses. In the meantime, the number of accidents has been decreasing every year along with the continuous expansion of exclusive median bus lanes as a result of rising public awareness and the establishment of an orderly traffic culture due to continuous promotion of the exclusive median bus lane system.

Since 2009, the Seoul Metropolitan Government has been improving 40 exclusive median bus lanes in the city – including the expansion of exclusive median stops (11 places) on Gangnam-daero – by promoting the 'Project for the Improvement of Exclusive Median Bus Lanes.'

In 2011, the exclusive median stops (11 places) on Gangnam-daero, where extremely crowded with bus users, were extended, with stopping phases increasing from 4 to 5 and platform width, from 3m to 4m. Also, a bus stop was newly established in front of Suyu Station on Dobong-Mia-ro to enhance the ease of transfer with Subway Line 4.

In the future, the Seoul Metropolitan Government will continue to improve the operational efficiency of the exclusive median bus lanes in accordance with changes in the local environments and traffic conditions by promoting such improvement measures as optimizing the intersection signal times and promoting bypass routes in order to alleviate congestion in the exclusive median bus lane on Wonsan-ro, which runs from Sinseol-dong to Cheongyang-ri. It will also consider expanding the stop of the exclusive median bus lane in front of Gyeongin Road dome stadium following its opening in the southwestern region.

In order to reduce traffic accidents in other sections, the installation of safety barriers around the exclusive median stops and crosswalks, shock absorbers at road junctions, photovoltaic rechargeable raised pavement markers for lane guidance, and speed prevention facilities at the stops was carried out along with regular safety education programs for bus transportation service workers. In addition, for some bus stops and general traffic congestion points where build-up occurs due to the concentration of passengers getting on and off (buses) after the installation of the exclusive median bus lanes, the Seoul Metropolitan Government will strive to resolve the inconvenience of bus users and drivers of general vehicles by carrying out various projects to enhance the capacity of bus stops and traffic improvement projects to relieve traffic congestion. It will also continue to improve upon factors that inhibit traffic safety and obstacles to communication by observing the traffic situation on sections within the exclusive median bus lanes.

In the future, the Seoul Metropolitan Government plans not just to construct exclusive median bus lanes, but also improve their functions by continuing to identify points on the sections currently in operation where traffic congestion and inconveniences in using the buses occur.