Benefits of Adaptive Vehicle Lighting
Exterior vehicle lighting (headlights and signal lights) typically provide static luminous intensities for forward visibility or to ensure that other road users can see a vehicle, especially when stopping or turning. Performance is specified by the Federal Motor Vehicle Safety Standard (FMVSS) 108, which in turn is based on a number of standards published by the Society of Automotive Engineers (SAE). With respect to headlights, technological developments such as high intensity discharge (HID) and light emitting diode (LED) headlights are providing the technical basis for headlight beam patterns beyond the simple low and high beams currently specified in FMVSS 108. Some developments, such as swiveling headlights that can turn to provide increased illumination when driving into a roadway curve, are permitted by FMVSS 108; others, especially some advanced forward-lighting systems (AFS) modify the beam pattern in response to specific conditions such as bad weather, or in the presence of other vehicles to reduce glare. Such modifications can result in a beam pattern not conforming to FMVSS 108.
The objective of the research summarized in this statement is to provide an objective basis for identifying whether and how much adaptive headlighting systems could improve visibility and safety (and reduce glare), and if so, in what situations safety benefits can be obtained.
It is widely recognized (e.g., Andre and Owens, "The Twilight Envelope: A User-Centered Approach to Describing Roadway Illumination at Night," Human Factors, 2001) that low beam headlights, which are the beam patterns used by most drivers in most situations (Mefford et al., Real-World Use of High-Beam Headlamps, 2006), are not sufficient in providing nighttime visibility at driving speeds greater than about 35-40 mph. Adaptive vehicle lighting might increase the use of forward lighting distributions conducive to safety but these benefits are not well-quantified, nor are
Among the research tasks needed are:
Evaluation of the visibility, glare and safety impacts of adaptive vehicle lighting strategies.
Assessment of the interactions between vehicle headlights and infrastructure based systems such as roadway lighting, highway signs and pavement markings.
Cost-benefit analyses to address the balance between system costs and potential benefits.
The research summarized here should be shared with SAE and with the National Highway Traffic Safety Administration.
|Sponsoring Committee:||ACH40, Human Factors of Infrastructure Design and Operations
|Index Terms:||Adaptive control, Headlamps, Light emitting diodes, Federal Motor Vehicle Safety Standards, Night visibility, Glare, Vehicle lighting devices, Vehicle safety, High beamed headlamps, |
Safety and Human Factors
Vehicles and Equipment