Colorado vs Utah

For families driving I-70 and I-80 between Denver and Salt Lake City, Colorado is the stricter of the two states, and the gap widened after Colorado's 2025 overhaul. Colorado requires a child under 2 to ride rear-facing, keeps a child in a car seat or booster through age 8 (booster to 9), and requires children under 9 to ride in the back seat. Utah sets no rear-facing age, releases a child from a child restraint at age 8 (or once they reach 57 inches), and has no back-seat requirement. On rear-facing, the booster, and the back seat, Colorado reaches further.

Under a law effective January 1, 2025 (HB24-1055), Colorado raised rear-facing to age 2 (unless the child is over 40 pounds), extended the booster requirement to age 9, added a back-seat requirement through age 8, and required everyone under 18 to be restrained. The violation is now a primary offense, so an officer can stop a driver for it alone. Utah's law has not seen a comparable update and remains a single age-8-or-57-inch standard with no rear-facing age.

Colorado requires rear-facing until age 2; Utah sets no rear-facing age. Colorado keeps a child in a booster until age 9; Utah releases at age 8 or once the child reaches 57 inches. Colorado requires children under 9 to ride in the back seat; Utah has no back-seat requirement. So a Utah family driving into Colorado picks up rear-facing under 2, a longer booster requirement, and a back-seat rule. Pediatricians recommend all of these in both states, but only Colorado makes them legal requirements.

Neither state fixes a single dollar figure in the same way in its restraint statute, though Colorado's violation is now a primary offense. The law that applies is the law of the state you are driving in. On a Denver-to-Salt-Lake trip, follow Colorado's stricter standard: rear-facing until age 2, a booster until age 9, and any child under 9 in the back seat. Pack to Colorado's rules and you will be covered on either end of the route.