Night markets are hardly new. Asia is stuffed with them. From Singapor's hawker centers to the jostling markets of Bangkok , excellent cheap food is available late into the night. (Source)
Now jostle has different meanings:
1: verb (used with object), jos·tled,jos·tling.
to bump, push, shove, brush against, or elbow roughly or rudely.
2: to exist in close contact or proximity with: The three families jostle each other in the small house.
In this context, does jostling markets mean a place where it is very crowded or a place where there are a lot of markets next to each other?