UNIVERSAL ACCESS R&D A significant amount of research and development on universal access has been conducted with the South African National Council of the Blind
Local standards for tactile ground-surface indicator (TGSI) systems require more clarity to ensure that visually impaired South Africans can safely navigate through city streets and buildings, says local universal access specialist company Future Mobility Engineering MD Frano Combrinck.
TGSI systems are detectable warning and guiding surfaces, which provide physical cues for the visually impaired, informing them of an obstacle or hazard ahead, such as a flight of stairs or a street crossing, as well as guiding them through a route or towards a pedestrian crossing. The systems are designed with small bubbled protrusions for warnings and elongated protrusions for guidance, which visually impaired people can feel underfoot or with a guidance cane.
He tells Engineering News that a significant amount of research has investigated the best TGSI solutions and configurations, but consensus has thus far been elusive.
Combrinck, a specialist consultant in the field of TGSI systems, notes that the Standard Construction Details and Design Standards for Intersection Pedestrian Crossings Affected by the Bus Rapid Transit (BRT) Infrastructure is the only documentation available to South African contractors entailing the detailed design of tactile pedestrian crossings for the visually impaired. It contains draft standards involving the correct design and layout of universal access systems for public transport infrastructure.
The document, based on research conducted on TGSI systems currently deployed in other countries, such as Australia, New Zealand, China, the UK and the US, and some African countries, was developed by black-owned engineering consultancy Gibb during the company’s work on the Tshwane BRT system.
Gibb was appointed by BRT operator Tshwane Rapid Transit (TRT) in July 2012 to design and supervise construction of traffic and geometric systems, including TGSIs, for the TRT line 2A trunk route from the Tshwane central business district to Hatfield. Gibb completed the project in September last year.
The TGSI systems used in the project were designed by Combrinck – a Gibb employee at the time – and Gibb roads and highways engineer Larissa Junkoon.
Combrinck is currently chairperson of a South African Bureau of Standards (SABS) working group developing tactile pedestrian crossings. He explains that the SABS, Gibb, the Department of Transport and a number of independent universal access consultants and experts are working with the South African National Council for the Blind to investigate which solutions and configurations work best. Combrinck is also part of the SANS 10400 part S working group, which deals specifically with universal access solutions in the built environment, particularly in buildings, but also includes some tactile applications.
Combrinck states that, while the research and development of TGSI standards is ongoing, contractors must follow the guideline set out by Gibb during the Tshwane BRT project as a starting point. “It is important to also consult a universal access consultant or specialist in the field for final design, as some small changes have been made in the last few months, owing to research that has been undertaken,” he concludes.