Purpose: A large part of maritime container supply chain costs is generated by carriers in port hinterland logistics. Carriers which operate in the hinterland are under pressure to reduce costs and increase profitability, and they face challenges of fierce price competition. This study aims to explore how collaboration is perceived and implemented by carriers in truck container logistics in the port hinterland as a way to tackle these issues. Design/methodology/approach: This study adopts a qualitative multiple case study approach. Qualitative interviews with carriers in the port hinterland of Hamburg, Germany, were conducted and analyzed using grounded theory. Findings: The study reveals two collaboration types in the hinterland, based on the different carriers' interpretation of market conditions as changeable or as given, driving their collaboration mindsets and strategic actions: The developer, who has a proactive collaboration mindset and practices strategic maneuvers toward changing poor market conditions through collaboration, and the adapter, who has a defensive collaboration mindset and perceives market conditions as given and constraining collaboration. Research limitations/implications: The qualitative results will help researchers better understand how collaboration practices depend on the carriers' subjective interpretations and perceptions of the market. Practical implications: Based on the findings, managers of carriers gain an understanding of the different types of actors in their market and the relevance of acknowledging these types. Consequently, they can design appropriate strategic measures toward collaboration. Originality/value: The findings for the first time provide exploratory insights of carriers' mindsets.