Since Changi was built, the highlighted portion of the highway (East Coast Parkway) leading to the airport was always available as a back up runway and/or crash strip.
The stretch is about a 1800m long and about 30m wide. The plants/vegetation you see in the middle are in large, easily removable pots with a wooden edging. The highway is lined with palms and lightposts but in a crisis it will be a small problem to clear these. What is important is that there seem to be no concrete structures next to this portion of the highway, being bordered on both sides by golf courses for the most part.
Anilv