# Presentation: 042289

## Pedestrians with Vision Loss or Blindness

## How many people are blind or visually impaired now

- 4.3 million Americans are severely visually impaired
- 1.1 million are legally blind
- Incidence increases with age
- By 2010, expect there to be 20 million visually impaired persons over age 45

## Variations in Vision Loss

## How do pedestrians who are blind or visually impaired travel?

## Pedestrians who are blind or visually impaired in the US do travel to new locations or intersections and ‘figure them out’ by listening and exploring

- Transportation choices
- Walk
- Bus or rail transit
- Taxis, friends, relatives, or paid drivers

## Obstacle detection and curb detection techniques

- Long white cane used as a probe of the walking surface
- Dog guide to used guide around obstacles or stop at curbs or dropoffs
- Low vision travelers may use their vision and an aid such as a telescope

## Orientation and alignment cues

- Detect slight slopes under foot and/or a detectable change in surface texture
- Listen to direction that cars are traveling to align to cross
- Listen to when the cars start moving in the closest lane as indication of time to cross
- Maintain awareness of buildings, sun, other pedestrians, smells, and sounds which provide information
- Ask a lot of questions

## Crossing at a signalized intersection

## Problem areas for travelers who are blind

- Locating the crosswalk
- Detecting a gap in traffic

## Locating the crosswalk

- Preventing crossing into the circulatory roadway
- Finding the crosswalk
- Aligning to cross

## Australia

## Slide 22

## Detecting a gap in traffic

- Hearing is not as specific as vision
- With vision, can select just one lane or area to check; not possible when crossing using audible cues only
- Pedestrians with low vision may have more difficulty with depth perception and judging speed

## Masking by other cars

- Cars that have just passed the crosswalk
- Cars in the circulatory roadway
- Car approaching in other lane of street the pedestrian is crossing
- Car that stops to allow the pedestrian to cross (multi-lane roundabout)

## Sighted pedestrian crossing

## Blind pedestrian crossing

## Ongoing Research

- National Eye Institute of the National Institutes of Health has funded a five year project on Blind Pedestrians’ Access to Intersections
- Roundabouts – blind and low vision individuals
- Accessible Pedestrian Signals
- Detectable warnings
- June 2000 – May 2005

## NEI-Supported Study of Roundabouts Access

- To date
- Evaluated gap judgments by sighted and blind individuals at 5 roundabouts with volumes from 12,000 to 35,000 estimated AADT
- 2 Single lane and 3 multi-lane

## NEI study - Traffic Volume

- Higher volumes yielded fewer crossable gaps
- Higher volumes resulted in more unsafe judgments, more missed gaps, and longer periods of time between the beginning of a crossable gap and the point at which a blind person detected it

## NEI study - Unsafe judgments

- Blind participants were more than twice as likely to make unsafe judgments as sighted participants
- Time of day differences
- Little difference between judgments of blind and sighted individuals at mid-day
- Substantial differences at rush hour

## NEI study – Latency and delay

- Blind pedestrians detected gaps later than sighted pedestrians
- Baltimore – 3 seconds later
- Tampa – 5.5 seconds later
- Blind pedestrians require longer gaps in order to detect the gap and cross

## Experience in other countries

- Reports from pedestrians who are blind or visually impaired indicate that roundabouts are often considered a barrier to independent travel

## Australia

- Individuals who are blind or visually impaired and Orientation and Mobility Specialists state that blind pedestrians
-  Avoid crossing at roundabouts
- Often severely limit where they can travel
- Roundabouts there may have detectable warnings and tactile guidestrips

## England

- Pedestrians who are blind or visually impaired state that roundabouts can be very difficult to cross
- Signals are installed at some roundabout locations, as are raised crosswalks

## Review - Problem areas

- Difficulty finding appropriate location to begin crossing
- Latency and delay in detecting gap, and subsequent inability to cross
- Unsafe judgments about gaps