A road you've never taken is one where both the journey, and the destination, is unknown. Each twist and turn, each bump and pothole, each time the road curves around a corner beyond what you can see, and each time it appears to lead you forward, only to double back before heading off again... yup, that certainly fits the description. And just as it is in life, the journey as well as the outcome isn't known before hand.
Why then would anyone ever take a road less taken, when it's safer to simply hew along a familiar path? The short answer: because that's how life works. We explore, we discover, and then we learn. It certainly doesn't hurt to get completely lost every now and then, if only for a chance to discover what we could be missing all along. That's life. Enjoy.
(Pixel-peepers: I was eyeing this winding road amidst the backdrop of a most unusual landscape. The scene looked interesting but it lacked a focal point. Nonetheless, I took one shot and moved on. Moments later I saw this biker bouncing down the trail. Could he be that missing element? The only way to find out was to try it. The road less taken.)