There is only 1 entrance bridge to the island, which will open at fixed times to allow ships to pass.
Unique Suggestions: Be patient. If you are in the middle of a traffic jam in Stralsund, better pay a short visit to this beautiful Hanze city.
2007 Update: End october the new Ruegenbruecke was opened. This new and high bridge makes an end to the lang waiting lines at the old draw bridge.
Fun Alternatives: Take the ferry south of Stralsund.
The the National Park is forbidden for private cars.
Unique Suggestions: Go to the Hagen Parking place and take the bus.
Fun Alternatives: If the weather permits take a bicycle (24 gears!)