Atkinson is an English-language surname. The name is derived from a patronymic form of the Middle English Atkin.
These are much more conservative than state laws, in general (for instance, everyone should be in a booster seat from about age 4 to at least age 8) but remain less conservative than some of the european standards (for instance, the European Child Safety Alliance recommends that children remain in rear-facing carseats until 3 years of age).
Car seat safety advocates recommend that babies stay in a rear-facing car seat to the weight limit of the seat or at least until age 2. The American Academy of Pediatrics recently revised their car seat policy to recommend rear-facing to age 2, as well. Several car seats today have rear-facing weight limits up to 40 pounds, which might accommodate the average child through age 3 and maybe beyond.