Originally Posted by
LIH Prem
There's a long history of updated rail to DMK and beyond, but the SRT (State Rail of Thailand) has always owned the right of way that the expressway and highway underneath the expressway follow. For years when DMK was BKK before the new BKK was built, there were columns built for a new rail project that ended up being abandoned and had to be ripped out for the new red line and high speed rail projects. I'm sure somebody here can point you to that history.
BTS does go to the airport, but it's the back side of the airport. Last year there was talk of building another monorail to connect one of the now opened BTS stations to DMK as well. Not sure if they are still planning that or not. You can see those new BTS stations in one of the videos transpac posted.
The AOT plans to build an internal APM - not monorail - between the old domestic terminal (T3) when it rebuilt by 2025 and T1 & T2 given that is is 1km from T1 to the domestic. Once this is built the plan is to extend it to the backside of the airport to connect with the BTS Sukhumvit line at N23. However, let's see if they build the first stage between the terminals first.