How do you say "U-shaped" in English? Quiz

For example, when you turn off a main road and enter a narrow road, you can only turn left,

In Japanese, a road where you have to turn left twice to get back to the original main road is called a

 

U-shaped" in Japanese.

 

in Japanese.

 

 

How would you describe the shaded road in the above figure in English?

Please answer with no hints.