POLICE are urging Johannesburg motorists not to stop their cars on the N1 near Mondeor after three drivers were murdered in seperate incidents this week. Most recently, Themba Daniel Mafume, 41, a Sebokeng resident, was murdered after he got out of his car to fix a tire. The modus operandi of the killers is to place a rock barricade in the road. When drivers stop to either remove the rocks or replace their tires, they are attacked and murdered. On Tuesday Randburg cyclist Johan Kruger was killed on his way home from the Argus/Pick ‘n ‘Pay Cycle Tour in Cape Town. He had stopped after his car hit rocks placed in the road. No arrests have been made. Meanwhile police have said they will increase patrols on the killer stretch of highway.