I was thinking of doing it but only went so far while I was mulling it over. Whilst I am joining the two splits together and then two-waying them are we sure that the speed data is not lost? Then again simplifying might be worth the lost data particularly on a short section of a busy road as it will get re-populated again fairly quickly?
Joining two one-ways together and then into a two-way doesn’t work. You will loose one set of data doing it. Only splitting a two-way into two one-ways works.
That still works, but looking at that, it is to preserve the house numbers if they have been added to the roads.
When the speed data was still available, I had checked the speeds of each one-way segment before. After merging and saving there was speed data for one direction.
As far as I can remember, I had used that method to unsplit a road the last time I had to do one. I didn’t have to worry about house numbers as virtually all our roads here don’t have them added.
I believe that the speed data is stored in the segment properties as A to B and B to A. If both segments have the speed data in the same direction (A to B) then there will be no data available to merge for the B to A direction.