California vs Oregon

California and Oregon both run on the I-5 corridor and both write protective car seat rules, but California is the stricter of the two. They agree on the two biggest rules: both require a child under 2 to ride rear-facing, and both keep a child in a car seat or booster until age 8 or 4 feet 9 inches. Where California pulls ahead is the back seat and the fine. California requires children under 8 to ride in the back seat where one is available; Oregon has no back-seat requirement. For most families moving up or down the coast, the booster question does not change, but the back-seat rule does.

Both states require rear-facing for a child under 2 (California adds a 40-pound or 40-inch exemption). Both then require a car seat or booster until age 8 or 4 feet 9 inches, with a child moving to a seat belt at that point. So a child who is correctly seated in Oregon is almost always correctly seated in California on the rear-facing and booster rules. Pediatricians recommend rear-facing as long as the seat allows and a booster until the belt fits in both states.

California requires a child under 8 to ride in the back seat where one is available, and it never allows a rear-facing seat in front of an active passenger airbag. Oregon recommends the back seat for young children but does not require it by law. This is the rule most likely to catch an Oregon family by surprise in California: a 6 or 7 year old who rides up front legally in Oregon must move to the back seat in California.

California's base fine is about $100 for a first offense and $250 for later ones, plus county penalty assessments. Oregon enforces its rule as a violation but does not set the same fixed dollar figure in the restraint statute. California is also changing in 2027: Assembly Bill 435 will require a seat belt to pass a five-step fit test, so a child who cannot pass keeps using a booster even after age 8 or 4 feet 9 inches. Oregon has no comparable rule. If your trips on the I-5 cross the state line, plan around California's tougher rules: keep a child under 8 in the back seat and in a booster until the belt genuinely fits, and your child will be properly secured no matter which side of the border you are on.