Despite opposition from some Klong San locals, construction of the BTS Gold Line from BTS Krung Thonburi to Taksin Hospital is expected to start this April. 
Prachachat reports that Krungthep Thanakom, the state enterprise that belongs to BMA, are awaiting final approval from cabinet for their proposed construction plan for the three-station extension, as well as approval from the National Environmental Board, which is currently reviewing an environmental impact assessment (EIA).
Looking likely to become the shortest BTS extension of all, the 2.7km project along Charoen Nakorn Road will be separated into two parts with a total four stations.
The first part consisting of three stations across 1.8km—Krung Thonburi (G1, next to the current BTS Krung Thonburi), Icon Siam Station (G2, next to the megaproject of the same name) and Khlong San Station (G3, next to Taksin Hospital, the hip Jam Factory compound and Klong San Pier)—is expected to be operational as early as next year. 
The second part of the project along Somdet Chao Phraya Road, comprising a fourth station at Wat Anongkharam (G4), will supposedly follow in 2023, covering another 0.9km. 
The proposed new BTS Gold Line
According to Surapong Laoha-Unya, Director and COO of the BTS, the B2.08 billion project will be at least partially funded by private groups, including Icon Siam, the mega mixed-use property featuring malls and residences that's set to open on Charoen Nakorn Road later this year.
The project's EIA should face close scrutiny because the Gold Line's proposed elevated track contravenes regulations that prohibit developments that obscure the scenery of Rattanakosin Island. However, the BMA has called for an exemption in this case by saying the proposed elevated track is cheaper compared to the alternative of an underground track. 
Krungthep Thanakom says the BTS has already expressed its intention to invest in the construction and operation of the line for 30 years. It plans to use a fully automated, driverless transit system for the operation, with two trains and three carriages carrying 80-100 people each. The Gold Line is projected to welcome 47,300 passengers a day for the first three stations, and 81,000 pasengers per day when the last station opens.
The Gold Line will cross, and potentially connect, with two other mass rapid train lines: the State Railway of Thailand's Red Line and the MRT Purple Line, which will have a station on Prachathipok Road.