This happened when I was an undergrad at NUS about 6 years ago.

I was riding along AYE, heading home one fine night after doing some mugging at campus. It was about 0930 and I was about to exit at Alexandra Rd when I noticed a figure with long loose white clothings and long hair waiting near the filter road. Although she was quite near the Expressway, somehow I didn’t managed to get see her face clearly. I didn’t pay much attention to the ‘lady’ because I thought she be waiting for a cab or somebody. But come to think about it, nobody flags a cab along the expressway and there are no buildings or structures nearby except for the perimeters of Alexandra Hospital where the main entrance is nowhere along that road.