As of March 2019, 14 percent of headlight systems tested on model year 2019 vehicles received a good rating. More than half were rated marginal or poor because of inadequate visibility, excessive glare from low beams for oncoming drivers, or both.
Why does headlight performance matter? It takes 1.5 seconds for a driver to react to an unexpected event under ideal conditions. At a speed of 55 mph, a car travels about 120 feet during this brief period. Once the driver applies the brakes, it takes more than 144 feet, on average, to stop at this speed.
A driver of a 2019 Honda Insight should be able to spot an obstacle in the left lane 174 feet ahead while using low beams and 458 feet ahead while using high beams. When traveling 55 mph, this is the difference between having 2.2 seconds to detect and react to an obstacle using low beams and 5.7 seconds using high beams.
The low beams of many headlight systems with poor ratings don't provide enough light for a driver going 55 mph on a straight road to stop in time after spotting an obstacle in his or her lane. They provide even less illumination on the left side of a straight road and when driving on a curve.
https://www.iihs.org/topics/headlights