Canada is less urbanized [than the US]

Technically true, but the difference is small: about two percent less of the population living in urban areas, which is the usual measure of urbanization. Canada has a smaller population and a larger land area, but most of its land is very sparsely populated. (Several European countries, incidentally, are less urbanized than the US by this measure, including Germany and the UK.)

It does seem to have fewer road fatalities by most reasonable measures, though. It's closest if the denominator is in distance driven, and even there the US is about 15% higher.