Why Do We Smack Into Each Other? (E89)

One day, Bonobono and Chipmunk are walking when Raccoon smacks into them at a crossroad. Raccoon yells, "Why did you smack into me?!" He says that if Bonobono hadn't dropped his shell and spent time picking it up, they would have passed each other with no problem. How can they avoid smacking into each other when they walk? (Crunchyroll)