Samantha Edwards, Individually and as Special Administratrix of the Estate of William Bobby Wray Edwards, and Arleigh Grayce Edwards, Deceased; And as Parent and Next Friend for Peyton Hale, a Minor v. Eric James Cornell Thomas and McElroy Truck Lines, Inc., 625 S.W.3d 226

On August 2, 2018 a tractor-trailer driven by Eric Thomas ran a stop sign and struck a pickup driven by William Edwards; Edwards and his two-year-old daughter Arleigh (unrestrained and weighing under 60 lbs.) died; a child safety seat was present in the vehicle.
Defendants (Thomas and McElroy Truck Lines) admit negligence but assert comparative fault/defense that Edwards failed to restrain Arleigh; they intend to offer expert biomechanical evidence that a properly used child seat would have prevented ejection and death.
Plaintiff (Samantha Edwards, as administratrix and parent) moved for partial summary judgment, arguing Ark. Code Ann. § 27‑34‑106(a) (Child Passenger Protection Act) bars evidence of failure to use a child passenger safety seat to prove comparative/contributory negligence.
Defendants challenged the constitutionality of § 27‑34‑106(a), contending it invades the judiciary’s exclusive rulemaking authority (separation of powers under Ark. Const. art. 4, § 2 and Amendment 80, § 3) by dictating admissibility of evidence.
The certified question from the federal court was whether § 27‑34‑106(a) violates the separation‑of‑powers doctrine; the Arkansas Supreme Court held the statute constitutional, reasoning it is predominantly substantive law (legislative policy choice limiting negligence liability), not an impermissible procedural rule.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Ark. Code § 27‑34‑106(a) violates separation of powers by barring evidence of failure to use a child safety seat	Edwards: statute is substantive—creates/defines a substantive rule that failure to restrain a child is not negligence and thus precludes the defense	Thomas/McElroy: statute is procedural—it dictates admissibility of evidence and encroaches on the Court’s rulemaking power under Amendment 80	Court: statute is more substantive than procedural; constitutional; does not violate separation of powers
Whether precedent (Johnson and Mendoza) requires striking statutes that incidentally touch on procedure or evidence	Edwards: prior decisions recognizing statutory substantive rules (and Mendoza distinguishing similar statutes) support upholding the CPPA provision	Defendants: rely on Johnson bright‑line rule that legislative provisions dictating procedure/evidence are unconstitutional regardless of conflict with court rules	Court: declined to overrule Johnson/Mendoza; nevertheless found § 27‑34‑106(a) sufficiently substantive here and upheld it; several justices concurred separately urging overruling of Johnson/Mendoza

Potts v. Benjamin, 882 F.2d 1320 (8th Cir. 1989) (federal case cited by plaintiff re admissibility/defense issues)
Mendoza v. WIS International, Inc., 490 S.W.3d 298 (Ark. 2016) (addressed seat‑belt statute and separation‑of‑powers; distinguished in this case)
Johnson v. Rockwell Automation, Inc., 308 S.W.3d 135 (Ark. 2009) (announced bright‑line rule that legislative provisions dictating procedure are unconstitutional)
Summerville v. Thrower, 253 S.W.3d 415 (Ark. 2007) (defines substantive vs. procedural law)
State v. Sypult, 800 S.W.2d 402 (Ark. 1990) (discusses deference to legislature unless court rule’s primary purpose/effectiveness is compromised)
Bedell v. Williams, 386 S.W.3d 493 (Ark. 2012) (upheld statutory testimonial privilege as substantive law)