The famous outdoor second story steps in downtown Montreal, an area they call Balconville because of all the open balconies with stairways, presents a real safety problem in those icy Montreal winters. The most common anti-slip treatment is to install a jute runner, commonly called Tapis CoCo. Concrete re-bars are hooked through eye screws to hold it all in place. The eye screws are often left all year long.
Some people use the sand in the paint technique, but that only works for wet, not icy steps, and wears off rather quickly. The modern replacement for the Tapis CoCo is a hard rubber mat that is screwed into place. When you whack the ice on top of this mat, the rubber gives just enough for it to break off easily. A tread pattern in the rubber gives it a good footing.
A far more designer orientation would be to use Tech Stone, an out of the bucket anti-slip designer treatment for stairs, steps, kitchens, patios and swimming pool walkways. It is actually textured stone in a base that will stand up to winter and even salt. You simply apply a primer, then spread the TechStone out 1/8th of an inch thick and smooth it off. You can combine colours as in the patio photo.