The strange route of Elin

When Elin and Jessica go from Agnes' house to Kristian's party, they take the short one-hour route.
But when Elin goes home alone to Agnes, she chooses double time because she goes over the school bridge.
I don't understand this big turn?

But when Elin goes home alone to Agnes, she chooses double time because she goes over the school bridge.
I don't understand this big turn?
