It's worth pondering that the overwhelming majority of police deaths are injuries when an inattentive driver runs over an officer during a traffic stop. Only a suicidal maniac would stand for an extended time on the drivers side of a stopped car on the highway. It would be a boon to public health if the police could just photograph a traffic offender and send him the ticket in the mail! The police unions would be disappointed, though, because then they can't use the statistics to argue for their members, because felony homicides of police officers are around 40/year in the US. That includes Greater Methville.
That's the main difference between police officers and highway patrol in my area: police go to the driver side window, highway patrol go to the passenger side.
But yeah, it seems like an unnecessary risk for police to go to the driver's side. I always try to give them space, but quite a few drivers don't.
