Risk of pedestrian collision for persons with peripheral field loss: A computational analysis

Area of Science:

• Vision science
• Human-computer interaction
• Biomechanics

Background:

• Peripheral field loss, such as homonymous hemianopia, can lead to pedestrian collisions.
• Previous models simplified pedestrians as points and did not account for the vision of non-impaired pedestrians in collision avoidance.
• Understanding collision risk in real-world scenarios requires considering pedestrians as volumetric entities with and without vision.

Purpose of the Study:

• To extend collision risk models for individuals with homonymous hemianopia by simulating pedestrians as volumetric entities.
• To characterize the collision risk posed by normally sighted pedestrians to those with homonymous hemianopia.
• To compare collision risks using point vs. volumetric pedestrian models, with and without vision.

Main Methods:

• Simulated approaching pedestrians as volumetric entities without vision, volumetric entities with vision, and as points.
• Generated spatial collision risk maps and densities based on bearing and radial distances.
• Analyzed collision scenarios involving individuals with homonymous hemianopia and normally sighted pedestrians.

Main Results:

• Volumetric pedestrian models showed slightly different collision risks compared to point models.
• Normal vision in the non-impaired pedestrian significantly reduced collision risk by enabling detection and avoidance.
• Remaining collision risks were concentrated at higher bearing angles (>50°) and closer radial distances (<2 m), primarily when overtaking.

Conclusions:

• Collisions are infrequent and occur when individuals with peripheral field loss overtake pedestrians from behind at higher speeds.
• Higher bearing angles represent a critical zone for potential collisions, necessitating monitoring by assistive aids.
• Findings are applicable to various peripheral field loss conditions, including monocular vision loss and conditions like retinitis pigmentosa and glaucoma.