The reason is the demolition of the bridge across Rama 4 leading to the Queen Sirikit Convention Centre as well as a flyover. Somewhat optimistically, an official from the BMA said
"We are also seeking cooperation from motorists to avoid the route while construction is under way"
Co-operation? This is going to lead to massive traffic chaos on lots of the roads in the area, and not just the major ones. Coming home this afternoon around 4:30pm, Rama 4 from Suriwong towards the motorway entrances was totally clogged and hardly moved. But then of course drivers can look forward to the relief that will eventually come - by about April 2021!
https://m.bangkokpost.com/news/general/ ... ause-chaos