A tourist that is already standing on a tile can not be moved to the last played tile, unless the last played tile borders directly on the field the tourist stands on. In that case you can use action 3c.
Of course the city will still consist of 16 tiles in the end.
Be aware: This variant makes it more difficult to play Cities, because you have more opportunities in placing your tiles. The game can also last a little longer.
The tile can be placed on fields with a tourist on it, but all affected tourists have to be removed from their fields and put back in stock.
After placing the tile, every player can move or place a tourist according to the normal rules.
Players are not obliged to place the extra tile. If they do not place the tile, they can still move or place a tourist.
With thanks to Nicoline who put me on track of this variant.
By the way: you can play all variants at every level of playing.
Go to the next page about Cities