I was reluctant to wear a helmet until my brother-in-law was knocked from his bike by another cyclist. He fell backwards onto the ground where he struck the back of his head with considerable force. The helmet he was wearing was badly smashed but he was totally uninjured.
Besides the matter of helmets, another contribution to safety on the roads would be the recognition that carelessness on the part of pedestrians and cyclists is likely to result in harm to themselves whereas carelessness on the part of motorists is more likely to result in harm to others.
Motorists should be much more aware of their capacity to harm others, or surrender their driving licences.