Recently they tested thirty-one mid-size vehicles for their headlights. This is the first time they've done this and the results are fascinating if not limited in their scope.
And...Vehicles can be equipped with different headlights, so there are a total of 82 headlight ratings for 2016 models even though there are only 31 vehicles. The Institute is rating every possible headlight combination as it becomes available from dealers.
The Prius v earns a good rating when equipped with LED lights and high-beam assist. To get those headlights, consumers must purchase the advanced technology package, which is only available on the highest trim level. When equipped with regular halogen lights and without high-beam assist, the Prius v earns a poor rating.
"The Prius v's LED low beams should give a driver traveling straight at 70 mph enough time to identify an obstacle on the right side of the road, where the light is best, and brake to a stop," says Matthew Brumbelow, an IIHS senior research engineer. "In contrast, someone with the halogen lights would need to drive 20 mph slower in order to avoid a crash."
Do read the whole article at the link above. It's worth a moment of your time and it's a wake up call to both vehicle owners and manufacturers. If you can't see at night, it's not your fault. It's almost certainly less than good headlights on the car.