It is a 90 mile drive, about 45 down to Daytona and then 45 to Orlando on I4. I4 toward Orlando in the morning rush hour and away from Orlando in the afternoon is a potential parking lot. Plan accordingly on weekdays. St Augustine itself is a beautiful old city with the traffic relatively confined to one main road and several very slow one lane alley's. A trip to the fort is interesting and if you feel like really being a tourist, a ride in one of the horse drawn carrages around town with a tour guide is a lot of fun. I'm not sure what traffic is like out on the island.