In the PRC in general both the terms 市郊铁路 (Urban-Suburban railway) and 市域铁路 (Perfectural railway) refers to newly-opened commuter/regional railway services in general interchangeably, and are designated with Latin letter S. In Southern Zhejiang province, however, 市郊铁路 refers to genuine commuter/regional lines like that of Transilien, while 市域铁路, dubbed with S, refers to the partially underground urban system like that of the RER.

Due to the state restrictions on rapid-transit building in smaller cities some city governments use this methods to circumvent such restrictions, branded as a rapid transit toward the citizens while as a commuter rail toward the central government.

[6][4] The west section of the line (34.38 km (21.363 mi)[7] with 12 stations) was opened on January 23, 2019.

The first phase of Wenzhou Rail Transit received official approval from the National Development and Reform Commission in September 2012.

[6] The first phase of Line S3 starts at Wenzhou Railway Station, along Wenrui Avenue, passes through Nanbaixiang, Xianyan, Tangxia to Rui'an City, then crosses Feiyun River to the south, passes Kunyang, Aojiang, Longgang, to Lingxi.

The second phase of this line, costing 26.40 billion yuan, extends over a length of 66 kilometers (41 mi) and encompasses 17 stations.

[4] Map showing operational and under construction lines of Wenzhou Rail Transit.