Only real place to ride fast on SSI is up to the north, as said above. There is maybe 10 miles of nice road with little traffic on it and they were building a bike path along that road when I was there last summer.The bike paths around the south 1/2 of SSI are uneven, slow going and suitable mostly for noodling around... also said above. If it was me I would drive to Jekyll to ride my bike. That is one high freaking bridge and traffic on it is fast.