Is the length of a URL a ranking factor when it comes to good SEO?

Short answer, NO

Yet, be careful, because in my opinion URL structure does matter. Proper structure reduces the total number of characters so they are by default, shorter. URL length defiantly affects usability, that’s for sure and usability is something search engines just love.

If you are making long URL’s for the reason of keyword stuffing, you are not helping yourself either. In the world of SEO you can go overboard, and a lot of webmasters do.

Keep in mind also that no page on your site should really be more then 2 clicks away from the homepage. This is something search engines pay attention too and from my experience IS a ranking factor. So as overall URL length really plays no role, there should be no reason why, for static URL’s that is, to have something overly long.