The best way to signal to cars that you are going to walk your bike across the street is to use hand signals. If you are walking your bike on the right side of the road, you would signal to cars that you are going to cross the street by holding your left arm out to the side and pointing to the ground. If you are walking your bike on the left side of the road, you would signal to cars that you are going to cross the street by holding your right arm out to the side and pointing to the ground.