Double-sided tape or tape made exclusively for stair treads can be added to slippery vinyl stair treads to provide traction. Use tape to cover each tread entirely or only the middle where it gets the most traffic. Replace the tape as needed; use a little adhesive to secure the tape to each tread if you are concerned about the tape ending up on shoe soles when they are walked on.
Tacky substances such as all-purpose adhesive may be applied to slippery vinyl stair treads. Adhesive can work particularly well in commercial buildings with concrete stairs and walkways that receive a lot of foot traffic; this prevents concern about adhesive getting tracked onto carpeting or hardwood flooring. Use an old shoe to go over the tacky substance a few times to work it into the vinyl treads though you can also opt to leave it as is.
Add pieces of carpet scrap to slippery vinyl treads to prolong their life. Use heavy-duty glue to attach the strips to the vinyl. As with double-sided tape, you can opt to cover the treads completely or use strips in the middle of the stairs only. Industrial carpeting works well, though fluffier carpet options may also be used. This option also lends itself to reusing carpet samples and pieces from other projects rather than throwing them out.
A final option for slippery vinyl stair treads is complete removal. These stair treads become slippery as a result of wear and tear as treads generally contain visible ribbed surfaces for traction purposes. Tread replacement is therefore a safe option once these ribbed surfaces have been worn away. If the treads are otherwise intact upon removal, they can be reused as automobile floor liners or as liners for cat litter boxes.