I do not think they are synonymous, particularly.
Hustle is not a verb I commonly use for movement, but it seems to imply a bit of roughness, disregard for others in your path if you hustle through a crowd. I checked in our dictionary and there are a variety of contexts listed, many of which surprised me (including the first one, "hustled off to work" ) as they do not sound common. I think of this more as somthing you do to someone else, like the second example, hustling the kids to school. Maybe it is used more in the US as something you do yourself?
Scramble implies effort, and thus can denote less speed than the other two. Also a hint of desperation, scrambling for the shore or to get a grip on something, perhaps.
Hurtle suggests great speed, like cars on a motorway or rockets in space.