Making mountain biking safer

While a vehicle may kill you when you're biking on the road, it's even easier to get hurt while riding your mountain bike, with some gruesome scratches and spectacular blood stains all over.

For the most part the danger inherent with mountain-biking are rocks on the trail, trees and bushes along the sides, many poorly designed turns and single tracks that are too narrow and mask good visibility. Should all trails be improved to address these dangers?

No, just the easier and most accessible ones that are aimed at more conservative and older users. This would enrich the participation and make it accessible to a large number of adult beginners and senior riders.