Isn't it just.....
Part of the problem is indeed them shopping and changing the configuration...... one day a set of lights are on, one day they are off, and there was once a through lane that worked well, which later got changed. They have made a right pig's ear of the alternative, The Railway Line Bypass, which has been renamed 'tour of scruffy backroads'.... which has been a suspension destroyer for over a year now. I have paid 10 baht and wasted fuel to use Hwy 36 and Hwy 7 quite a number of times, but beware weekend Bangkok traffic.