What is the difference between an obstacle departure procedure or an ODP and a standard instrument departure?, or a SID? Both can actually be printed graphically, though SIDs are always graphical, and ODPs are usually textual. But the difference comes down to their purpose. An ODP solely exists to keep you clear of obstacles on departure. The route that it takes may not be optimal for traffic flow, but it will keep you clear of obstacles. On the other hand, a SID—a standard instrument departure