Table 1.

Summary of Variables for Child Restraint Laws

Category	Sub-category	Description/Notes	Variables
Which children are protected under the law	Age of child a	The age range at which a child passenger is required to use a child restraint device/rear seat/seat belt	Minimum and maximum ages for infant seat, toddler seat, booster seat, and non-specified general child restraint (8 variables)
	Weight of child a	The weight range at which a child passenger is required to use a child restraint device/rear seat/seat belt	Minimum and maximum weights for infant seat, toddler seat, booster seat, and non-specified general child restraint (8 variables)
	Height of child a	The height range at which a child passenger is required to use a child restraint device/rear seat/seat belt	Minimum and maximum heights for infant seat, toddler seat, booster seat, and non-specified general child restraint (8 variables)
	Miscellaneous	Whether the law requires a child passenger to be restrained until the age AND height/weight requirements are met (as opposed to OR)	Yes/No binary variable for infant seat, toddler seat, booster seat, and non-specified general child restraint (4 variables)
What action should be taken in order to comply with the law	Type of restraint device required	Whether the law specifies a device type (such as a booster seat) depending on the child’s age, weight and/or height	Yes/No binary variable for existence of explicit infant, toddler and booster seat laws, as well as implicit laws for each (6 variables)
	Quality of restraint device	Whether the law requires the operator to use only those devices that meet federal or state safety standards	Yes/no binary variable for infant seat, toddler seat, booster seat and general child restraint (4 variables)
	Method of installing and using a restraint device	Whether the law requires the operator to use devices in a manner consistent with physicians’ and or scientists’ recommendations (e.g. placing an infant seat in a rear-facing position)	Yes/no binary variable for infant seat (rear-facing), toddler seat (forward-facing) and booster seat (strapped with seatbelt) (3 variables)
	Seat belt substitution	Whether the law allows the operator to substitute a child restraint device with a seatbelt (usually when the child passenger at issue is above a certain age, weight and/or height limit).	min. age, max. age, min. weight, max. weight, min. height, max. height, whether the substitution is allowed after the age AND weight/height requirements are met (7 variables)
How the law is enforced	Primary enforcement vs. secondary enforcement	Whether law enforcement officers can stop the vehicles solely based on noncompliance with child passenger safety laws or not	Yes/no binary variable for child restraint law (1 variable)
What the penalties are for non-compliance	Type of penalty	Whether there is a fine, license points, insurance points, or mandatory education requirement	min. fine, max. fine, min. license points, max. license points, min. insurance points, max. insurance points, existence of mandatory education for the violation (7 variables)
	Waiver	Whether there is a first-time waiver, a fee waiver for indigent populations, or a waiver for subsequent proof of restraint device purchase or education program attendance	existence of each waiver (3 variables)
Who should comply with the law and who is exempted from doing so	Exemptions	See Table	See Table 3 (23 variables)

^aSome states combined two or more of the three categories in defining its target child group (e.g. “a child who is less than X years old and weighs less than Y is required to use a restraint device”) or used either/or terms (e.g. “a child under the age of X or the height of Y is required to use a restraint device”).