ROCKVILLE, Md. — Another collision in a Maryland work zone.
This time involving a state trooper in Montgomery County.
It happened around 1am on the outer-loop of I-495 near Greentree Road .
The trooper was guarding the zone in a lit up marked cruiser, when a Honda Accord came up and rear-ended them.
Police say the driver, 37-year-old Nithya Ramani, was arrested for driving while impaired.
Neither Ramani or the trooper were injured, although both cars had to be towed..