Non slip outdoor stairs treads

[Richard Krokodiliukas]

Tenant and I agreed before signing the lease that I would install something on the outdoor wooden stairs to his 2nd floor apartment to make them less slippery during the winter. I narrowed to 3 options: grit tape, vinyl treads or carpet cover mats. Metal treads are too expensive. What do you use? I'm in PA and we get a lot icing in the winter.