It is obvious that the conditions faced by bicyclists on our cities' roadways has changed a lot in 50 years. By age 10 I was riding my bike all around a city of 150,000+ which didn't involve getting on any multi-lane facility or speed limits faster than 35 mph. By now we have eliminated the grid pattern, widened streets and turning radii, forced most of the traffic onto thoroughfares/arterials, and increased speed limits. I can see why people are now concerned with even letting a 13 year old travel throughout a city on a bike.