The scene looks moderately busy. It's hard to say if that's what you're going for based on not knowing what the environment is/time of day/normal traffic flow would be for the scene.
Depending how far the scene stretches back, you could cluster some less detailed silhouettes in the far back and it'd give the illusion that the scene was much busier. Either way, I wouldn't add any more (or too many more) people to the foreground since people don't tend to clump together in big groups as much- so the pockets of people you currently have makes sense