One misconception I run into frequently is that it's necessary to design wider paths in order to make a labyrinth wheelchair-accessible. This false assumption is understandable in light of the accommodations required for most public spaces under the Americans With Disabilities Act (ADA). However in the case of labyrinths, the only people who seem to feel wide paths are necessary are those who don't actually use wheelchairs!
For those who do rely on a wheelchair, the width of the path is not important. They navigate the path using the "V" between their knees. To create and maintain a meditative state, you want the wheelchair user to concentrate only on that "V" and not be looking over the side of their chair or worrying about going off the path. Once they achieve a meditative state, they will cut all corners short of the true turns and it won't matter as long as they remain focused on the path (and so long as they know the surface is solid all around them). Intruding on adjacent paths with the wheels (or with a walking frame or other mobility aid) may seem inconvenient to other users but in practice it is rarely a problem - labyrinth walkers are used to accommodating others on their journeys!
There are other reasons not to make the paths wider. Wider paths in a given space means simplifying the labyrinth design, and reducing complexity reduces the richness of the experience and thus effectiveness. Oversized paths and a set number of circuits can result in an over-long labyrinth walk which ultimately feels tedious. Wider paths encourage greater walking speed, which can degrade the meditative experience for many regular walkers. Part of good labyrinth design includes deliberately slowing people down to increase contemplation - narrower paths encourage this effect.
We have designed and built more than 2,000 wheelchair-accessible labyrinths in a wide range of settings and materials. In the end, what makes a labyrinth accessible is simply having a flat, barrier-free two-dimensional surface that's solid and reliably weight-bearing. Concrete paver bricks, cut stone, decorated poured concrete, and the combination of stone lines with packed stone dust paths all meet ADA specifications for outdoor installations. In climates where grass thrives year-round, we have designed grassy paver labyrinths: a plastic, weight-bearing grid is planted with grass, while stone arcs or pavers are incised to form the lines of the design. Virtually all interior floor labyrinths and even portable floor mat labyrinths meet ADA specifications.
Often our clients add features to make their labyrinth more accommodating to folks who choose not to walk for whatever reason. An example is the lucite Breamore finger labyrinth installed at St. Luke's Episcopal Church in Bethesda MD. This is permanently mounted adjacent to the large turf labyrinth we designed, and enables mobility-impaired (or sight-impaired) visitors a means to share the experience.
Before you make special design accommodations for wheelchairs, have someone who uses one to take a test ride in a traditional labyrinth made with accessible materials. Then ask them if wider paths would make a difference to them, especially if this required significant simplification or enlargement of the design. I'll bet they tell you, "not really."