After lugging around a lot of cameras, lenses, etc, for a couple decades, beginning in the mid-70s I began to carry less and less if walking. I now carry a medium Billingham bag, a gift from my wife, and a camera along with one, two or three lenses ( depending on type of camera. The bag also contains a sketch/notebook, miniature watercolor set and a book. The Billingham is now almost 20 yrs of daily use and, except for a faint coffee stain I put on the first day of ownership, shows almost no wear. Good value for the buck.
When traveling by car I use appropriate fitted cases for my Leica, Leicaflex and Hasselblads and accoutrements for extra safety.