My brother and his wife have been riding around the world on motorbikes collecting dogs, you can checkout their blog here.
In order to safely collect dogs they created a dog carrier specifically for motorbikes called the Pillion Pooch. It’s been well tested and I know their dogs love it. Now they’ve just started a kickstarter campaign to put the wind in more dog’s faces. I think it’s a great idea and I can’t wait to see a random biker exploring the highways with their dog using this product.