Sixth Circuit ruling emphasises impact of alternative designs on assessing trade dress functionality

In DayCab Co Inc v Prairie Tech LLC (22-5625; 6th Cir; 11 May 2023), the US Court of Appeals for the Sixth Circuit reversed and remanded a district court's summary judgment ruling, finding that there were genuine disputes of material fact with regard to whether the plaintiff’s alleged trade dress was functional and therefore excluded from trade dress protection.

The district court’s ruling

DayCab, a manufacturer of conversion panels for tractor-trailer cabs, made Lanham Act and Tennessee Consumer Protection Act claims against Prairie Technology for trade dress infringement of its DayCab conversion kit. Prairie denied infringement and counterclaimed for declaratory judgment that DayCab’s trade dress was functional.

DayCab asserted that its conversion kit’s slant-back design, depth, rounded edges and grey colour were protectable trade dress, explaining that it had carefully selected the product’s angles, curves, tapers, lines, profile and appearance. The plaintiff further argued that the 144-degree angle of the slant-back design, the dimensions of the depth and radius of the design and the colour were aesthetic and not functional.

In support of its argument, DayCab presented competitor conversion kits to illustrate the range of appearances and styles on the market. The plaintiff also attested that its only manufacturability requirement is that the top of the fibreglass mould used to make the conversion kits be slightly larger at the top than at the bottom. In response, Prairie presented expert testimony that the parties’ respective kits were not identical and that the panel’s depth, top body radius, lower body angle, flange/body radius and colour were functional.

The parties eventually filed cross motions for summary judgment. Prairie argued that DayCab could not prove that its trade dress was non-functional, had secondary meaning or that there was a likelihood of confusion. The district court granted Prairie’s motion, finding that DayCab’s asserted that the trade dress was functional and therefore not protectable; its ruling did not address secondary meaning or likelihood of confusion. DayCab appealed the decision.

The Sixth Circuit’s reversal

The Sixth Circuit reversed the district court’s summary judgment ruling, finding that it did not answer key questions about whether DayCab’s conversion kits’ slant-back design was functional. It also remanded the ruling because the district court did not consider whether Prairie’s kits infringed DayCab’s design.

Regarding the functionality of the conversion kit, the Sixth Circuit determined that the existence of alternative designs and testimony from DayCab’s founder on the aesthetic nature of the company’s design choices conflicted with the district court’s functionality ruling. The appeal court also noted that the existence of alternative designs was relevant to the functionality determination because they supported DayCab’s contentions that it designed its panel with aesthetic intent and that the resulting features were ornamental rather than functional.

The Sixth Circuit ruled that it is up to the jury to determine the secondary meaning and whether Prairie intentionally copied DayCab’s design.

The court came to the same conclusion with regard to the likelihood of confusion due to conflicting evidence: DayCab presented evidence that consumers inquired about ordering Prairie’s kits from DayCab because the products were similarly named and indistinguishable on the road, while Prairie argued that conversion kits are only purchased by sophisticated consumers who understand the distinct marketing and packaging differences between the products.