Not sure the lack of traffic lights and an overpass in place will improve things.
We've seen plenty of examples where it makes things worse. In place of a good 4-way intersection roughly the size of the one depicted, is the Lanna interchange in Lampang, 93km south of Chiang Mai, which now has an overpass bridge BUT it does not cater for all directions. If you are coming from Lampang/Phayao and want to turn right to Chiang Mai, they've blocked the right hand turn lane and replaced it with a concrete barrier and there's no ramp designed to take traffic over to the Chiang Mai direction. Instead you have to turn left then do a u-turn almost a km down the road (absolutely ridiculous) or you continue straight for around a km or so, then do a u-turn, or you continue for 2 or 3km then make a right hand turn at the T-junction onto the feeder road, go along that for like 2km, then turn left at the big intersection nearby the aforementioned Lanna interchange.
The whole project is a total mess.
Another example is the turn towards Aranyaprathet along rte 304 in Phanom Sarakham district of Chachoengsao province. There's an overpass bridge allowing you to turn right in the direction of Aranyaprathet if you're coming from Bangkok/Chonburi, but going in the other direction, you can no longer turn right onto rte 304 in the direction of Prachinburi/Nakorn Ratchasima. You have to turn left, drive about a km, do a u-turn and come back. Previously, there was a perfectly good t-junction with traffic lights that worked just fine, allowing vehicles to turn in all possible directions and except during holiday periods, it was never particularly busy either.
Thai highway engineers are making things WORSE, not better. If they're going to replace traffic lights at intersections, they need to design interchanges allowing traffic to move in ALL possible directions, as is possible at an intersection. By blocking off right hand turns, they're shooting themselves in the foot.
Never seen any other country design roads this way.