Does anyone know what this is about?

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It appears to be a short section of 4-lane highway between sections that are dual-carriageway. Is this what you’re asking?

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Which road data? Can you be more specific?

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aha, it was a work in progress.

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Maybe I’m guilty - I remember changing the Lomsak section of road to dual-carriageway after riding through it. The section you refer is correct in that there is a length of single carraigeway where u-turns can pretty much be made anywhere along it. I GPS’d the start and end of the d/c sections so unless Bing shows differently, assume its right.
But as Dave suggests, perhaps I failed to add it back in when doing the upgrades… human error !

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