abstract: We consider the regular Lagrangian flow $X$ associated to a bounded divergence-free vector field $b$ with Sobolev or BV regularity. We prove a Lusin-Lipschitz regularity result for $X$ and we show that the Lipschitz constant grows at most linearly in time. We moreover discuss under which conditions, the flow $X$ inherits the Sobolev or BV regularity of $b$. Part of the work is done in collaboration with Paolo Bonicatto.