What is an inexpensive way to prevent slipping on ice on my deck?

I have an old pair of houseshoes that I've applied rough grit sandpaper to the soles using adhesive. I keep them by the door for when I have to venture outside for short trips such as retrievivg the mail. It works for me.

Prevent Slipping On Ice

Asphalt shingles nailed or stapled to the ramp will work very well on that. Nails will last longer, and use roofing nails. But you have to be careful, if shovelling, not to just pry them up again. Sweep snow off instead with a very stiff broom or garden rake. Keep sand and/or salt, or "ice melting compound" handy to spread around if what you get is frozen condensation overnight. Metal mesh is very good too, but harder to find and install and hard to get ice or packed snow out of. If you must walk across the deck, I'd get a cheap runner rug, rubber backed. Keep up with the snow removal on the ramp so it doesn't get packed down and frozen on.

You do not say as to the treatment on the ply. Painted varnished or what? Obviously they need treatment or the ply will quickly disintegrate. There are paint on the market especially for non slip areas. Boat yards use them for decks. Search the web for non slip decking paint and there are loads there to choose from

You can use sand or a very fine gravel to give you better traction, but the downside will be it gets tracked back into the house.

walk extra carefully

paint it, seal it, whatever. while its still wet sprinkle clean dry sand on it

Put down salt.