Motorcycle Safety & Driveability: tail lights, yamaha r600, diesel locomotives

Question
i have a '06 yamaha r600. i was wondering, may tail lights (turn signal lights) their not on at all times like the fronts are but, the turn signals work. my question is, do i need a two purpose bulb in the tail light(i've pulled them out and is just a single) or is that just the way it is?

Answer
The motorcycle's lighting system is designed that way. That doesn't mean you can't change it.

If the fronts are on all the time, and blink when you use the turn signal, those are called "marker" lights or "position" lights. They help other drivers judge your approach. Other drivers often misjudge a bike's speed and distance, because the single headlight and smaller size of the vehicle make it seem smaller and farther away. The marker lights add some perspective and help other drivers judge how far away you are and how fast you're going. Diesel locomotives use a similar system with their "ditch" lights. Of course, those also help the engineers see the areas around the track, but the approaching 3-beam headlight pattern is unmistakable, no?

Marker lights are left off the rear because the advantage is not there, especially with bikes in which the turn signals are incorporated into the taillight. If you have rear signals that are on a different visual line than the taillight (i.e. lower) then it's probably worth the effort to install marker lights there, too. They're just special bulbs, to the best of my knowledge, but they may also require a different switch to make them work.

Hope that helps.

Pat