Deploy and Test a Smartphone Based Accessible Traffic Information System for the Visually Impaired

Principal Investigator(s):

Chen-Fu Liao, Former Researcher, Mechanical Engineering

Project summary:

An increasing number of Accessible Pedestrian Signals (APS) have been installed at new or upgraded intersections to assist people with vision impairment to navigate streets. For un-signalized intersections and intersections without APS, people with vision impairment have to rely on their own orientation and mobility skills to gather necessary information to navigate to their destinations. Previously, a smartphone-based accessible pedestrian system was developed to support wayfinding and navigation for people with vision impairment at both signalized and un-signalized intersections. A digital map was also created to support the wayfinding app. This system allows a visually impaired pedestrian to receive signal timing and intersection geometry information from a smartphone app for wayfinding assistance. A beacon using Bluetooth Low Energy (BLE) technology helps to identify a pedestrian's location when he or she travels in a GPS-unfriendly environment. A network of Bluetooth beacons ensures that correct traffic information is provided to the visually impaired at the right location. This project leveraged the previous work by installing the system at a number of intersections in downtown Stillwater, Minnesota, where MnDOT operates the signalized intersections. In this study, researchers interfaced with the traffic controllers to broadcast traffic signal phasing and timing (SPaT) information through a secured and private wireless network for visually impaired users. The aim was to test the smartphone-based accessible system and evaluate the effectiveness and usefulness of the system in supporting wayfinding and navigation while the visually impaired travel through signalized and un-signalized intersections.

Project details:

  • Project number: 2019004
  • Start date: 07/2018
  • Project status: Completed
  • Research area: Transportation Safety and Traffic Flow
  • Topics: Pedestrian, Safety