Very true.
As a light source in of itself has no scale, and if assumed to be from a larger source (Truck, etc) then a smaller source will be interpreted as further away. For example: There are cases where a driver saw another car's reverse lights, and thought they were distant headlights, and that they had more time before they approaching car would get to them......only to find that they were MUCH closer reverse lights, too late to avoid a collision.
For this reason, adding the lighting of the TERRAIN is best for approaching motorists, as they see the CONTEXT of the approaching obstacles. IE: A scale to the object is provided, and appropriate reaction time can be more accurate. If they see the bike and the road/curb/curve/intersection etc, they have the best chance of correctly deciding on what degree of swerving, braking, etc, would be better. A brightly lit area draws attention, as the eye naturally goes to the "hot spot". Adding a beacon and/or strobe to the terrain lighting FURTHER draws the eye to it, as motion also attracts attention.
If the light illuminates the bike itself, that allows a sense of scale (They know about how big a bike is...) and therefore a sense of distance to it. If the terrain is also illuminated, its adds information as to what they might hit or miss if they try to avoid the bike, as well as adding a larger attention getting area to get their attention in the first place, and so forth.
