Halogen lights are the traditional bulbs used for headlights. However, Light-Emitting Diode (LED) and High Intensity Discharge (HID) lights are quickly gaining popularity.
The main differences among the light types are the heat output, light brightness, electricity draw and the cost. While LED and HID lights are more expensive, they offer benefits in the other categories. They both shine brighter and further on the road than traditional halogen lights. They also pull less electricity from your vehicle, put off less heat and last longer.
If you take a look at the safety each type of headlight offers, LED and HID headlights offer brighter lights that light up further ahead of the vehicle.
Safety ratings like the IIHS Top Safety Picks look at headlight design as a factor in determining ratings. The IIHS tests specifically measure how far past the front of the vehicle a headlight illuminates. It measures multiple aspects of the light; how far forward it illuminates on sharp and gradual turns, how far high beams go, as well as the regular headlights in both the right and left lanes of a road. Most of the IIHS tests tend to show LED and HID headlights score better on these tests.