Let X be a set of positive reach in the d-dimensional Euclidean space. We p
resent formulae for the integrals of the curvature measures of flat section
s of X with respect to ail translations/Euclidean motions of the sectioning
flat. We consider the (generalized) curvature measures supported by the co
rresponding unit normal bundle. As a special case we obtain formulae for th
e spherical area measures.