Bicycle Helmet Safety Institute

Consumer-funded, volunteer staff

Helmets Children Promotions Statistics Search

CPSC Guidelines for Age-Related Activities

Summary: Guidelines for ages when children are ready to use wheeled toys and vehicles from the US Consumer Product Safety Commission

The best guidelines we have seen were on the CPSC site:

Age Determination Guidelines: Relating Children's Ages To Toy Characteristics and Play Behavior

Note that an individual child's development rate may be very different from average expectations. CPSC updated the guidelines in 2020.