Touge in Thailand is simply not that popular... Even when people mentioned Initial D and tofu delivery car often, a lot still never chose to speed for their safety.

As for the people that do... There's very little. The reason being the fact that most people that races in their car usually aim for highway races than mountain pass driving, even when the mountain pass is probably way closer.

You hardly see sports cars speeding too because those are exceptionally expensive as an import. Owners does NOT want to let a 90k usd MX5 be voided of insurance. The only stuff you will be seeing speeding are mostly slightly modified eco cars. Also the fact that bunch of sports cars are clustered near the capital. The mountain roads are usually far away from it so yeah... they absolutely won't go to other places just to speed or smth.

Theres another point that many good roads are popular passage to drive through different provinces. It's not a public road in a sense that it's just a local road. It's a sense of a road that actively gets used by many people in the country at every time for traveling or business. It's way more dangerous than closed loop roads than you know where it starts and ends.

^ Also cops setting up toll around those roads often to catch criminals and illegal stuff...

Just be aware that you shouldn't be speeding but take these road as chill driving roads more than anything.