So, I took the plunge and bought the L&M ARC HID light. It's overkill for the tunnels--my original reason for getting a light. Having done a lot of reading and thinking about night riding, however, I decided to outfit myself with something that would allow me to do it properly (I also bought a mack daddy Cat Eye taillight). It could end up being a really expensive experiment or the best money I've spent on my bike.
Ironically, I went for a ride on Monday that despite being theoretically in the daylight, it was really hard to see. I would have benefitted from some lights even in those conditions.
Thanks for all the great advice.
Kate
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher