Transport simulations including in-medium properties derived in a microscopic π+NN - 1 +ΔN - 1 model in infinite nuclear matter are presented. In-medium pion dispersion relations, partial Δ decay widths, pion absorption cross sections and Δ cross sections are incorporated into the transport description by means of a local-density approximation. Strong modifications of π and Δ production and absorption rates are found, but only small effects on pion observables.