As Rory and Lorelai walk to Luke’s for early coffee and breakfast, Rory explains that they can’t walk past Doose’s Market in case Dean is working there (she can’t remember if he is, but earlier he told her their anniversary dinner had to be on Friday as he was working on Saturday night). They can’t walk past the high school in case Dean is playing football, and they can’t walk down Peach Street because that’s where Dean’s house is.
The unique configuration of Stars Hollow means that the only three routes to Luke’s Diner are now cut off from them and they have to walk through an alley to get to breakfast, as staying in and getting their own coffee and breakfast is apparently just not possible.
The real question is why they are walking at all – they have a car, and don’t they have a lot of things to buy, not to mention taking all their stuff to the recycling centre? How are they managing all that on foot?