High levels of traffic can cause social isolation and limit interpersonal networks of support, factors which have been found to be associated with higher mortality and morbidity in the elderly. Children who have the opportunity of playing unhindered by street traffic and without the presence of adults have been found to have twice as many social contacts with playmates in the immediate neighbourhood as those who could not leave their residence unaccompanied by adults due to heavy traffic.
Certain patterns of transport have a broad range of effects on mental health, including risk-taking and aggressive behaviours, depression and post-traumatic psychological effects of accidents.