I'm sure this varies from one locale to another, but in my experience in various parts of the US, virtually all urban roads with extra width have it just for parking. Much of the time the parking is so full that there's no room for delivery vehicles and passenger dropoff/pickup to use anything but the travel lanes, and even when there is room they often can't be bothered.

There are places where space is carved out just for loading and not parking, but it's not the common thing, especially in residential areas.