It's not a big issue in most parts of the U.S. - few parents would venture out in traffic on a bicycle themselves let alone allow their children.
Children under 12 shouldn’t bike alone.
Children who have not yet turned 12 aren’t ready to bike alone in traffic according to a new study by researchers at Umeå’s University Hospital. The study, which is presented in the medical journal Läkartidningen, shows that young children lack the capability to predict what might happen in traffic. Also, their simultaneous capacity isn’t properly developed – if they turn their heads, they are having problems steering, which makes them especially vulnerable in traffic. We should add that in Sweden most people, if not all, bike on a daily basis to work as well as to school.
Children under age 12 shouldn’t bike alone in traffic, as their senses aren’t properly developed, making them especially vulnerable for accidents.