The cost of knowing: How obstacle alerts reduce walking speeds of augmented white cane users

To ensure safe passage blind travellers utilize mobility aids such as the white cane to preview the space their body will move through. Augmented white canes (AWC) have increased this preview range to reduce collisions, but consequently incurred lower walking speeds. The literature has blamed the slowdown on the AWC provided alerts that are additional to white cane feedback, unnecessary, too complex, and the anticipatory slowdown of their users. Two within-subject studies with six visually impaired and ten blindfolded people compared the white cane to two different AWC preview types (See Figure 1) combined with two ranges to investigate the causes of the slowdowns. The cognitive cost from processing AWC additional and unnecessary alerts and their complexity slowed users down and should be kept to a minimum as they neither helped reduce collisions nor physically detecting obstacles with the cane.