  In this contribution, we present a novel approach for solving the obstacle
problem for (linear) conservation laws. Usually, given a conservation law with
an initial datum, the solution is uniquely determined. How to incorporate
obstacles, i.e., inequality constraints on the solution so that the resulting
solution is still "physically reasonable" and obeys the obstacle, is unclear.
The proposed approach involves scaling down the velocity of the conservation
law when the solution approaches the obstacle. We demonstrate that this leads
to a reasonable solution and show that, when scaling down is performed in a
discontinuous fashion, we still obtain a suitable velocity - and the solution
satisfying a discontinuous conservation law. We illustrate the developed
solution concept using numerical approximations.
