State police said Drew Spencer, 27, was hit about 7:30 p.m. Sunday during a traffic stop on Interstate 96 east of Lansing near Webberville.
Spencer was airlifted to the University of Michigan medical center in Ann Arbor.
State police said Spencer and his partner had stopped a vehicle for a traffic violation on eastbound I-96 and were returning to their patrol car when another vehicle struck the patrol car and Spencer.
The 49-year-old Novi man driving the car that struck Spencer had non-life threatening injuries.
Drew Spencer is a trooper assigned to the Michigan State Police post in Lansing.
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