The Yellow Line

Project Website Lat Phrao - Samrong

Project Website:


        According to the feasibility study on economics and environment and the preliminary design of the Yellow Line project which was undertaken by Office of Transport and Traffic Policy and Planning (OTP) during the years 2007-2011, the Yellow Line project was divided into 2 sections, i.e. Ratchada/Lat Phrao-Phatthanakan section and Phatthanakan-Samrong section, or The Yellow Line(Lat Phrao - Samrong). The MRT Yellow line has officially opened for revenue service since July 3rd 2023.


      The Yellow Line(Lat Phrao-Samrong) is the straddle monorail system on the elevated structure, 30.4 kilometers with 23 stations. It is the interconnecting line between the Blue Line at Ratchada station (Lat Phrao station of the Blue Line) and the other 4 lines of mass transit system, i.e. the Grey Line(ฺBMA) at Chalong Rat intersection, the Orange Line at Lam Sali intersection, Airport Rail Link at Rama IX interchange and the Green Line: Bearing-Samut Prakan at Samrong station.

The Project Route alignment (Lat Phrao – Samrong)

      MRT Yellow line project is elevated straddle type monorail transit. The route start from the interchange station with the M.R.T. Chaloem Ratchamongkhon Line (THE BLUE LINE) at Ratchada - Lat Phrao intersection and head to Lat Phrao road, connect with Grey Line Project (Project of BMA) at Chalong Rat intersection, cross Chalong Rat Expressway to Bang Kapi intersection. Then, the route head toward south on Srinagarindra road, connect with the Orange line Project at Lam Sali intersection, cross Rama IX interchange, connect with the Airport Rail Link. The route will head through Phatthanakhan, Si Nut, Si Udom, Si Iam, Si Thepha intersection, Thepharak road toward the Green Line: Bearing-Samut Prakan at Samrong station and ends up at Pu Chao Saming Phrai road. The entire length of the Pink Line contains the distance of 30.4 kilometers.


     Depot area of the Yellow Line Project was located on the Si Iam interchange on Sri Nakarindra road. The depot area consists of Main workshop for Rolling stocks inspection and maintenance activities, Stabling area and Operation Central Control building.

Park and Ride Building

     Park and Ride building of Yellow Line project located near Si Iam station on Sri Nakarindra road. Full capacity around 2,800 cars.

Rolling Stocks 

     The 750 Volts DC rolling stock with 4 cars train will be used since initial phase and might be expanded to be 7 cars train in future operation which can contain passengers around 28,000 passengers per hour per direction.

     Rolling Stocks of The Pink and Yellow Line system is the first driverless straddle type monorail in Thailand. Maximum operation speed is 80 km/hr. Train interior was design based on universal design concept which contain facilities and safety features. Overall 30 trainsets contained in this project.

Power Supply System 

     Monorail Project’s Power Supply System connect to the power supply system with MEA at 115kV through the bulk substations (BSS) which located 2 areas (in Depot area and mainline). BSS convert the voltage 115 kV to 24 kV to distribute to Service Substation ( SSS) which supply the power to all M&E equipment in every stations and Traction Substation (TSS) which convert Alternative current to be 750 V Direct Current through Conductor rail on mainline for rolling stock propulsion.


     The signaling and communication of this line will be the same as those of the Chaloem Ratchamongkhon Line. 

Guideway Beam    

     Guideway beam will be parallel installed along the route with walkway for passengers evacuation. Conductor rail was mounted along the beam for train power supply. There are 2 type of guideway beam in the project.

     1. Concrete guideway beam – general type of 30 meters beam used in the project.

     2. Steel guideway beam – length 20 – 70 meters, this beam type was used in the limited condition route such as narrow curve radius route and long distance across the canal or junction.

Depot and Workshop Equipment  

     Depot and Workshop Equipment are installed/stored within the Main Workshop building. This equipment includes the Maintenance - Inspection Vehicle (MIV), as well as various tools and machinery used for repairing and maintaining the tracks. Among these tools are the 2-ton and 5-ton overhead cranes, the Bogie Maintenance Work Station (BMWS), tire inflation equipment, and cleaning facility such as the Train Wash Plant.

Platform Screen Door 

     Platform Screen Door System is a set of gates that act as a barrier between the platform and the railway track along the entire length of the platform. This system is implemented for the safety of passengers. The doors used in this project are of the half - height platform screen door type.

Automatic Fare Collection System  

     Passengers are able to travel in MRT system using single-journey ticket/prepaid ticket or credit cards which be compatible with EMV, where the data is sent to the Clearing House. This helps facilitate the systematic management and monitoring of fare collection.

Project Cost

Land Acquisition
million baht
Civil works
million baht
M&E Works and Rolling Stocks
million baht
Consultant Fee
million baht
million baht

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