"... car at least partly on the pavement, this is to shield them from traffic..."

We used to do that, officers still got picked off by passing traffic (I have had big rigs actually brush my fanny as they went by at 55++ mph). Then we got smart and started walking up on the passenger side of the violators vehicle, staying away from the traffic completely. Muchomore safe that way. Officers (and violators) still get run over, but not nearly as many...