NUTS is when you want to do something and you seek approval of a higher authority. When there is no rule saying that you can do such a thing, then the standard answer is NO …

In the US, when there is no sign on the road, it means that you can make a U-turn. When the authorities do not want people to make U-turns, they will put up signs to tell you not to make U-turns. In Singapore, it is the reverse. When there is no sign on the road, you are not allowed to make U-turns. When the authorities allow you to make U-turns, then they will put up signs to give you that right.

The two different systems serve the same purpose – to better manage the traffic. They may look quite similar, just coming from different directions, but the social repercussion is significant.

- Chaotic Thoughts from the Old Millenium, Sim Wong Hoo, Creative Technology Pte Ltd, 1999

Source: http://sgentrepreneurs.com/commentary/2011/10/28/progress-made-but-singapore-government-still-micromanaging/