Wintertime in Toronto normally results in icy front steps and on older homes, these steps are often made out of concrete block. Because of the block, a lot of early homes were built without railings because the owners were younger at the time of buying :-); and, hollow block is difficult to install railings into without cracking them. The latter point has changed over the years and there are now a number of good concrete plugs that work.
In the case below, the son bought the railings online and asked me to install them. We matched them up with the railing around the porch and best of all, he bought two! There is a dramatic reduction in falls on stairs if two railings are there as opposed to one. If the person is holding a bag or package, it ensures they have at least one hand on a rail. If they are just walking in, two rails just makes them more secure. Greater security here results in going out more often, better and improved quality of life.