The forward blind zones of six top-selling vehicles grew over the past 25 years as pedestrian and bicyclist fatalities soared, a new comparison technique developed by the Insurance Institute for Highway Safety shows.

The U.S. Department of Transportation’s Volpe Center used the new method developed by the IIHS developed to measure a driver’s direct area of vision around a vehicle.

The DOT study found that over multiple redesign cycles from 1997 to 2023, forward visibility within a 10-meter radius fell as much as 58 percent for three popular SUVs. For a top-selling pickup, close-proximity visibility declined by a smaller 17%, but even the earliest model had massive blind zones. In contrast, the early models of the two cars provided relatively good visibility that fell less than 8 percent in later generations.

Researchers who wanted to compare blind zones for different models needed engineering drawings or position each vehicle in an open area specially marked with grid lines or traffic cones. The new IIHS method relies on computational software and a portable camera rig that can be positioned in the driver seat at various heights to represent different-sized drivers.

IIHS researchers are currently working on comparing blind zone maps for 150 vehicle models, exploring the effects of different-sized blind zones on pedestrian crashes and examining the relationship between blind zone sizes and insurance losses.

The DOT researchers used the new IIHS technique to examine how the designs of the Chevrolet Suburban, Ford F150, Honda Accord, Honda CR-V, Jeep Grand Cherokee and Toyota Camry changed over model years 1997 to 2023. The effort required blind zone maps of 17 individual vehicles, representing each major redesign of the six study vehicles.

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During 25-year period studied U.S. pedestrian fatalities rose 37 percent and bicyclist fatalities rose 42 percent respectively. There is no one clear reason cites for the dangerous trends, but previous research has linked the rises to factors like population growth in areas with poor pedestrian infrastructure, speed increases and changes in vehicle size and shape.

Recent IIHS studies have also shown that the height of a vehicle’s front end amplifies the effect of higher crash speeds on fatality risk and that vehicles with blunt front ends are more deadly than those with sloping profiles.

However, little is known about what role changes in driver visibility have played in the increase.

The DOT study focused on forward visibility within a 10-meter radius of the vehicle because that is the average driver stopping distance at 10 mph, a low speed at which blind zones are a common factor in crashes. They calculated the percentage of the 180-degree area that was unobscured by obstacles like the vehicle hood, the rearview mirror and the A-pillars, according to IIHS.

The biggest reduction came for the Honda CR-V, as the vehicle’s hood, mirrors and A-pillars all obstructed a greater portion of the driver’s view over time. Drivers of the 1997 model were able to see 68 percent of the area 10 meters in front of the vehicle, while drivers of the 2022 model can see only 28 percent. Similarly, drivers of the model year 2000 Suburban were able to see 56 percent of the area 10 meters in front of them, while drivers of the 2023 model can see only 28 percent, according to the IIHS.

The forward visibility provided by the F-150 also declined. Drivers of the 1997 model could see 43 percent of the forward area within a 10-meter radius, and that dropped to a 36 percent by model year 2015.

This article was originally published by Claims Journal.