Two of the roads used for the Singapore F1 race track has to be opened to traffic every night says Whiting.

Charlie Whiting, FIA race director - Singapore.
The only complication is that we have to open up two of the roads every night to traffic, so there’s an enormous amount of work to move barriers away and then back into place. So far we’ve been very lucky with the weather here. It rains quite often in Singapore and when it does, it’s usually heavy.”