A year ago I got tooth bonding (composite resin) to close a gap now Im worried about BPA?
Maybe. You need to talk with the city planning department. Another solution would be to put speed bumps on your street. A lot of the streets in my neighborhood have them.
Purely theoretically: if the light source were removed (anything that can generate light could absorb it), the light would bounce around forever. In reality, there is always some absorption, but consider a fiber optic cable a few microns wide and a few kilometers long: it is an exercise for the student to calculate how many reflections occur, and there is a loss of only a few dB in the best materials.