Like most great designs, the best ramp designs are those that exist largely unnoticed by most people. The most successful ramp designs are those that seamlessly integrate into the built landscape, specifically those designs that make stairs redundant and easily eliminated. That is the goal of “stramp” design.
In any discussion on ramp use, it is important to establish who the users might be. There are, or course, wheelchair users with either manual or motorized chairs; people who use assisted walking devices such as walkers, canes or crutches; people using strollers (or prams); even the occasional young person wearing skates.
“Stramps” are not a particularly new idea. One of the first examples was designed by Canadian architect Arthur Erickson for Vancouver’s Robson Square in the 1970s.
But with a growing understanding of the need for universal accessibility, the concept has seen a re-emergence across North America and beyond.
A stramp is a term used to describe a combination of stairs and a ramp. Stramps are meant to allow full accessibility to anyone where there exists a level change between the ground level and the entrance to a building.
Are stramps Great Design?
Unfortunately, stramp designs are not a panacea for the issue of accessibility and there are some serious problems that can result from inferior designs.
Stramp designs cannot have handrails along the full length of the ramp as they would block passage for anyone using the stairs.
Depending on the “rise” (the distance between the ground level and the entrance), a stramp should, but rarely does, have a rest area after a 20-foot (6 metre) distance.
Difficulty for people with reduced visual capacity
In some cases, it can be difficult for anyone with limited vision to distinguish where one step ends and the other begins, creating a potential danger. One solution might be to use a “contrasting strip”, a change of texture, material or colour, that would denote the edge of a step.
In bright light, shadows can trick the eye into seeing solid ground that doesn’t exist and, in the rain, visibility can be further reduced, virtually eliminating the normal visual signs of steps.
In stramp designs, handrails are rarely or infrequently used because, as previously mentioned, they would block the stairs from being used.
But people who are severely visually impaired rely on handrails for guidance through any obstacle, specifically where stairs begin and end. Anyone with limited mobility who does not use a wheelchair relies on handrails for safety and stability. Furthermore, some wheelchair users will use handrails to pull themselves up a ramp.
There are also several issues that the able-bodied need to negotiate.
Except at the extreme end points, stair users will find no flat landing point upon reaching the ramp surface. This means that when leaving the last step of the flight, the foot lands on an angled surface which has the potential to cause stumbles and falls.
For the steps to exactly meet the ramp, the step rise will occasionally have different heights. Uneven rise-to-run rations on a flight of stairs have been proven to cause accidents wherever they occur (https://inspectapedia.com/Stairs/Stair-Build-Uneven-Surfaces.php).
Ideally, the run-to-rise ratio for a functional ramp is between 1:15 and 1:20 or in metric measurement, 1:12 to 1:15. This means that for every 12-inches or one metre of rise, 15 to 20 feet or 12 to 15 metres of run is required for a ramp to be practical and comfortable to the user.
In stramp design, incorporating a correct run-to-rise ratio into a design that is practical for everyone is nothing if not difficult, and the higher the rise, the more difficult the task becomes.
Sometimes, it is impossible to avoid a steeper rise, but in those cases, it is important to understand that a steeper slope will require greater strength and control by the ramp user.