Can these steps be installed with only one handrail? What is the specific width of the treads with no handrails on?

Per the factory: The width of the treads is 36? or 74? (whichever size you get), with the handrails it adds another inch or 2 to each side of the overall dimension but does not affect the tread dimension. These steps can be used with 1 handrail. Just don?t install the second handrail. The stability of the step is not affected by this.