Oh, sorry, I didn't necessarily intend my comment to be relevant to the OP. The US 30 example just popped into my head when I saw the thread title.
I can understand why TWLTL's are not used in other countries, as they have numerous safety issues that relate to driver expectations. I would much, much rather have a proper median than a TWLTL, especially on roads with four or more lanes.
Not strictly on topic here - Another weird thing I have seen in Canada is a three lane road where passing is allowed on the side with only one lane. That strikes me as very unsafe and having the potential to get messy in a hurry.