The Cameron Gulbransen Kids Transportation Safety Act of 2007 requires the National Highway Traffic Safety Administration (NHTSA) to “initiate a rulemaking to revise Federal Motor Vehicle Safety Standard 111 to expand the required field of view to enable the driver of a motor vehicle to detect areas behind the motor vehicle to reduce death and injury resulting from backing incidents, particularly incidents involving small children and disabled persons.” It goes on to state that this may be accomplished “by the provision of additional mirrors (emphasis added), sensors, cameras, or other technology to expand the driver’s field of view.” An advanced notice of proposed rulemaking was published on February 27, 2009. This paper examines whether rear-mounted convex mirrors could provide an image with sufficient quality that may be useful in aiding drivers in performing backing maneuvers.

There are three main configurations of rear-mounted convex mirrors:​ a single “look-down” mirror, a single corner mirror, and a pair of cross-view mirrors. NHTSA measured fields of view and image quality of one look-down mirror and three pairs of crossview mirrors for passenger vehicle applications. Field of view and image quality were also estimated for one rear convex corner mirror based on previous research with that mirror relating to its use on medium straight trucks. Note that this study did not attempt to examine whether drivers will successfully use rear-mounted convex mirrors to successfully detect obstacles or pedestrians behind a vehicle. This question of potential overall effectiveness of rearmounted convex mirrors, relative to other solutions to expand the driver’s rear field of view, will be the subject of additional agency research.

The useful fields of view (FOV) of the five rearmounted convex mirrors were determined. The potential backover risk reductions were estimated for the five mirrors studied, using only that portion of their FOV’s with an image quality rating of better than “impossible.” The estimated potential backover risk reductions ranged from 33.4 percent (for the Toyota 4Runner rear cross-view mirrors) to 2.2 percent (for the ScopeOut™ passenger car rear crossview mirror).