As you head north out of Cruz Bay [1] on Route 20, also called North Shore Road, you leave behind the bustle of town and in less than half a mile enter the Virgin Islands National Park. Immediately, the air feels cooler, the landscape more lush, and it is quiet. This is quintessential St. John [2]: powder white beaches, pristine coral reefs, hiking trails, and awesome overlooks. No trip to St. John is complete without traversing this part of the island.
You can drive along most of the north shore. Route 20 extends from Cruz Bay to Annaberg, passing a half dozen excellent beaches along the way. Make a point of stopping at each of the half dozen overlooks (always on the seaward side of the road), to enjoy the view and let any faster-moving traffic pass you. If you have time for only one driving tour of St. John, make it the North Shore Road.
Links:
[1] http://www.moon.com/destinations/virgin-islands/st-john/sights/cruz-bay
[2] http://www.moon.com/destinations/virgin-islands/st-john