Question about the Battle of Hoth

Upon a rewatch of Empire Strikes Back- which I still adore now as much as I did when I first saw it- I realised something that kind of bothered me.

When the Rebel transport ships are leaving Hoth, they have to evade a Star Destroyer. My question is though, why did they have to go that way? There weren’t Star Destroyers circling the entire planet, surely they could’ve gone in any other direction other than the one area the Star Destroyers was guarding?