On the section of highway between Thayang and Phetchaburi, close to Outlet Mall https://www.google.com/maps/place/%E0%B ... 99.9168784, there are lots of incredibly tall trees, that I have rarely seen elsewhere.

 

Does anybody know what species of tree these are and how so many have managed to survived at this particular location?

They look like ... https://en.wikipedia.org/wiki/Dipterocarpus_alatus

 

They have a large "helicopter seed" that can fly for 100's of metres. We have a few of these trees near to our house in Sattahip and we can collect dozens of seeds from our garden after a strong wind.

 

I've also heard them called Thai Mahogany. It's definitely a hardwood (deciduous), but I'm not sure that it's a true mahogany (I'm no expert though).

Also known as Yang Na Yai tree - tallest tree in Thailand.

Fantastic!!!! Tall trees, and spreading the knowledge on a Sunday. Great! Thanks!

Thank you for the replies.

They are the same majestic species that lines the 200 year old Lamphun Road in Chiang Mai. This makes me think, that this stretch near Phetchaburi was also some part of an older route before the main highway was built.  It sure looks that way on Google Maps.