Skip to main content

Rensselaer Polytechnic Institute (RPI)

Study Shows High-Intensity-Discharge Headlights Improve Night Visibility

June 19, 2001

Study Shows High-Intensity-Discharge Headlights Improve Night Visibility

Troy, N.Y. — Researchers at the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute report that HID (high-intensity-discharge) headlights enable drivers to see more effectively at night than conventional tungsten-halogen lights.

The LRC study has recently been featured in USA Today and on the NBC Nightly News.

Based on field experiments in which drivers responded to objects in their field of vision while using both sorts of lighting, LRC researchers concluded that drivers using HIDs were better at “detecting edge-of-roadway hazards, such as pedestrians and animals.”

The study was conducted by John Van Derlofske, head of transportation lighting at the LRC, and lighting scientists John D. Bullough and Claudia M. Hunter, and was reported at a recent World Congress of the Society of Automotive Engineers.

Philips Automotive Lighting, an LRC partner and a major manufacturer of HIDs, commissioned the study.

“[HIDs] produce more light, last longer, and use less energy,” Van Derlofske said. “There’s no question they result in better visual performance. Now we’ve quantified that,”

HIDs are widely used on European automobiles and are growing increasingly popular in the United States. The National Highway Traffic Safety Administration has ruled HIDs do not exceed maximum illumination standards.

The study acknowledges criticisms leveled against HIDs that the bulbs produce more glare, and urges further study to quantify HID glare. “The problem with glare should be weighed against the improved visual benefits,” the report says.

Contact: John Van Derlofske (518) 687-7100
John Bullough (518) 687-7138

Contact: Patrick Kurp
Phone: (518) 276-6531
E-mail: N/A