Reflections on New Round Planning and Design of Metropolitan Circle Rail Transit Lines

(Chairman of Shanghai Urban Construction Design and Research Institute (Group) Co., Ltd., Senior Engineer)

JIANGYinghong

(Chairman of Shanghai Urban Construction Design and Research Institute (Group) Co., Ltd., Senior Engineer)

Shanghai Master Plan (2017—2035) has proposed construction of ′three-1 000 km′ rail transit network to adapt to its demand of multi-level spatially differentiated development. According to the planning concept of ′one network, multiple modes, wide coverage, high intensification′, rail transit network consisting of three levels of intercity line, urban line, local line is established. In this context, the suburban railway and rapid rail are unified under category of ′suburban line′ because of their functionalities. The history of international metropolitan urban rail transit development reveals that with evolution of urbanization from single-center city to multi-center metropolitan circle and urban cluster, urban rail transit development emphasis will extend from urban line to both ends of suburban line and local line.

Suburban line is a rail transit system that connects metropolitan circle center city urban area and surrounding suburban clusters, providing public transport service of high speed and large capacity for commuting passenger flow. It can adapt to Shanghai′s demand of building comprehensive transportation system of ′strengthened hub, manifested network′, effectively supporting and guiding urban system optimization and promoting accumulated development in core area. Suburban line creates traveling passages between new towns and city center, between new towns and cities close to Shanghai, achieving goal of ′30, 45, 60′, which is: internal travel and arrival in surrounding center towns within 30 mins, arrival in cities close to Shanghai, center city and neighboring new towns within 45 mins, travel between the two major hubs Pudong and Hongqiao within 60 mins. Taking the Shanghai Rail Transit Line 16 that has Shanghai Urban Construction Design and Research Institute overseeing its overall design as example, since the full line launch at the end of 2014, big station transport for 45 mins and direct transport for 34 mins from Lin′gang Dishui Lake to Longyang Road hub are gradually launched as well. Last year, the 3+3 online uncoupling technical application of flexible formation switch between peak hours and non-peak hours is realized, affording the functionality of rapid linkage between Lin′gang New Town and city center.

The background of new round metropolitan circle development gives the author a new perception of the suburban line functionality: Shanghai suburban rail transit network displays ′grid-scribed′ layout in general. Suburban line provides facility body to afford internal-external transportation switching functionality for cities close to Shanghai (e.g. Taicang, Kunshan, Jiaxing), and is a key component of Shanghai suburban rail transit network ring lines (e.g. suburban line ring passage composed of Baojia Line, Jiaqingsongjin Line, East-west Link Line) and radioactive line system. With suburban travel demands rapidly increasing and diversification of travel purposes during regional integration advancement, the average boarding times will drastically increase, and the passenger flow benefit brought by internal-external switching functionality will be gradually raised. Meanwhile, based on the definition of urban rail transit station center surrounding influencing range, considering suburban line station features, our Institute proposes a method for determining entry/exit, forming an eclipse influence range of 600 m. From current traveling data analysis, the suburban line passenger flow is even more uncertain because of the switching functionality. We are seeking a change from attention on passenger flow OD (origin-destination) to service of guiding passenger, establishing urban development area with suburban stations as core. Starting from station surrounding station-city integration design, build passages between tertiary industry cities, and accentuate the establishment of young people comfortable living and working ecology. Implement land use of station surrounding transportation facilities including medium capacity public transport, non-motorized transportation, parking facilities and smart traveling, and realize convenient connection among various transportation facilities.

Local line affords the functionality of urban line densification in urban core area, and the functionality of backbone public transport inside new towns, realizing arrival by public transport within 30-40 mins. Recently, National Development and Reform Commission has formulated Key Points of Low Capacity Urban Rail Transit System Planning and Construction during ′14th Five-Year Plan′, and China Association of Metros has issued Guidance on Low Capacity Rail Transit System Engineering Construction Procedure, proposing a series of policy and construction procedure requirements on low capacity rail transit system represented by tram. Local line represented by low capacity rail transit system and bus rapid transit (BRT) will become the new round main means to afford backbone public transport functionality in part of city center, or suburban clusters, five new towns. On 7th July 2022, Ministry of Housing and Urban-Rural Development, and National Development and Reform Commission issued the ′14th Five-Year Plan′ for National Urban Infrastructure Construction, pointing out that: ′Classified urban rail transit construction is promoted. Type I large cities should promote the construction of the main backbone network of rail transit in accordance with the actual situation, and study and utilize the rail transit system with medium and low capacity to adequately strengthen the network coverage, approaching networking operation benefit as soon as possible; Type II big cities shall promote the planning and construction of the rail transit system with medium and low capacity according to local conditions in combination with the urban traffic demand. ′ There are 15 type I large cities, 62 type II big cities in China at the moment, and low capacity rail transit system is an adaptive choice for these cities, supercities, and some areas in megacities. For cities planning and developing low capacity rail transit system, two suggestions are put forward:

First of all, lay stress on the integration of the three networks in planning layout. The line network planning and construction planning of low capacity rail transit within the concept of overall public transport should be scientifically devised. Refine networking operation planning in advance and focus on passenger flow benefit improvement. Reinforce research on functionality positioning and passenger flow demand, and appropriately deal with the connection with other ground public transport means. Implement land use of facilities connecting low capacity rail transit system and suburban line, urban line. It is suggested to carry out the transportation development strategy of ′core public transport priority area′, forming multi-level urban public transport network system.

On the other hand, build construction mode oriented by ′economically adaptable, low-carbon environment-friendly′ operation. Build local line networking operation mode through multiple ways including internal networking of local lines, local line + suburban line, seamless passenger sensation. Costs can be lowered by selecting mature and reliable system format that matches the functionality positioning and passenger flow scale, so that passenger flow is attracted in maximum, and efficiency is elevated adopting measures including intelligentized system.