The problem is, when you start making up your own rules, nobody else knows what you've made up. If I were in a car, seeing a cyclist pointing to the road would NOT tell me they were going straight. Maybe they want me to put my bumper *right there.* I hope you understand the necessity of yielding to existing traffic before changing lanes - no matter what obstacles are in front of you. Popping out in front of a semi could have adverse consequences, no matter how much glass is on the shoulder.