With the level of traffic at WDW walking/biking on the roadways is dangerous and NOT allowed. Security does patrol and will stop pedestrians and bikes.
There used to be a dirt pathway through the woods but it was never authorized and is now overgrown with foliage and critters. I would not try to go that way any longer and you would need to cross a busy WDW roadway to even get there.
Instead, take a bus to DS and switch to a POR bus.