The Biloxi Bay Bridge carries US 90 across the mouth of the bay, and the current span — opened in 2007 to replace the one Katrina destroyed — has a separated lane for walking and cycling along its length.
It is high, it is long, and it gives you the only elevated view available on this coast: the Back Bay behind you, Deer Island lying end-on to the south, the Biloxi peninsula and the casino towers to the west, and the Sound running away towards the barrier islands. On a clear evening it is the best free viewpoint in Harrison or Jackson County.
Allow twenty-five to thirty minutes to walk one way at an unhurried pace. There is no shade, so this is a morning or an evening activity between May and September, and it is properly windy in a front.
Cyclists use it constantly and it links the coast's bike routes on both sides. If you have rented bikes in Biloxi, riding over to Washington Avenue for lunch and back is one of the better days out here and costs nothing but the rental.