Abstract: There are two structural types of buried road & railway crossing pipelines: with casing and without casing. Discusses problems of strength, stiffness and stability of both types of pipelines. Gives a calculation formula and parameter values, and puts forward a new viewpoint on examination of strength and stiffness. It is thought through actual case analysis that elastic unstability of crossing section is unlikely to occur in crossing steel pipelines when conformable with minimum wall thickness limit as per specification requirement.