Large Driver-Side Blind Zones Increase Pedestrian Crash Risk

New IIHS research shows that vehicles with large driver-side blind zones increase left-turn pedestrian crash risk, highlighting visibility factors.

The latest research from the Insurance Institute for Highway Safety highlights a long-standing issue that many drivers sense but rarely quantify: limited visibility during left turns. The study shows that vehicles with large driver-side blind zones are about 70% more likely to strike pedestrians while turning left compared with those that offer a clearer forward view.

The problem stems from several design elements working together. Thick A-pillars, bulky side mirrors, and tall hoods all contribute to obstructing the driver’s field of vision. Using a camera-based technique, researchers measured blind zones in 168 vehicles from the vantage points of two common driver heights—5 feet 9 inches and 4 feet 11 inches. For an average-height driver, the blind zone blocked about 27% of the area to the left and front of the vehicle.

The risk rises further when the windshield field of view becomes too narrow. An angle of 85 degrees or less between the A-pillars was associated with a 51% increase in left-turn crash risk. Another critical factor is the nearest visible point on the ground: when this distance exceeded 30 feet, the likelihood of a crash rose by 37%. In such moments, a person in the crosswalk can simply disappear from sight as the driver begins turning.

Interestingly, an analysis of 3,500 crashes found that passenger-side blind zones had no significant effect on right-turn crashes. The heightened danger is concentrated almost entirely on the driver’s side. This is especially notable against the backdrop of a grim long-term trend: pedestrian deaths in the United States have increased by 78% since 2009, now exceeding 7,300 fatalities each year.

IIHS researchers stress that addressing the issue will be challenging for automakers. Many design features that reduce visibility simultaneously enhance occupant protection—thick pillars contribute to roof strength, for example, while long hoods improve front-end crash performance. Even so, some solutions such as side-view cameras, better-tuned pedestrian automatic emergency braking, or hood airbags could mitigate the problem without compromising structural integrity.

Infrastructure changes can also play a role. Traffic lights that give pedestrians a few seconds to start crossing before vehicles are allowed to turn can make them more visible to drivers. Curb extensions move waiting pedestrians further into the driver’s line of sight and shorten the time they spend in the roadway.

Ultimately, the study underscores a key point: driver visibility is a fundamental safety element that has not received the attention it deserves. With reliable tools now available to measure blind zones precisely, researchers expect the findings to influence both future vehicle design and urban safety planning.