Hi there,
Yes, these crystal blocks can be walked on. Thanks for the interest!

We at Swift Track, Inc. have developed and patented the only glass block installation system with internal illumination capabilities, for the “Thin Line Series Blocks”. This system utilizes a uniquely extruded clear acrylic channeling profile, along with an injection-molded connector, which guarantees simplicity and perfection. Swift Track was designed to take into consideration the more complex commercial applications for some very dramatic and colorful, visual effects. Amazed by Swift Tracks design and ease in which one can introduce color and light, Swift Track has become the system of choice for residential and commercial builders, Hotel and Entertainment Chains, Architects, Designers and Homeowners. Because of the unique, clear, profile extrusion, two ½” channels act as chases to house fiber optics, rope lighting, even LED strips to illuminate your glass block project.