I put cinder blocks in the back area near the wheels in my wagon and that works well. It allows me to climb hills that I normally wouldn't make with just the snow tires on it. I only put the blocks in when the roads are covered or snow is forecasted. I would recommend the sand bags if you have many hills in your daily commute. It cold mean the difference between getting home or staying stuck in traffic because of someone who wasn't prepared for the conditions.