The transition toward zero-carbon propulsion technologies has highlighted the urgent need for specialized test infrastructure to support hydrogen and alternative fuel research. This paper presents the conceptualization, design, and operation of a High-Pressure Direct Injection (HPDI) Hydrogen Internal Combustion Engine (H2 ICE) test facility with integrated ammonia fuel testing capability, marking a significant advancement in India’s sustainable automotive research efforts. Drawing from practical experience, it outlines crucial technical specifications, safety protocols, and best practices for establishing robust, adaptable, and secure testing environments. Addressing the industry’s need for dedicated infrastructure, it is engineered for adaptability across various engine types including heavy-duty, light-duty, and multi-utility vehicles while aligning with global technical standards. Key technical considerations include a transient dynamometer with an advanced automation system for precise control of both hydrogen and ammonia test cycles. Emission measurement systems such as hydrogen analyzer, ammonia-specific FTIR, particle number counter, and particle size distribution analyzer, are essential for analyzing regulated and unregulated emissions that are critical to sustainable fuel development. The hydrogen fuel storage and distribution system support up to 500 bar pressure, incorporating certified components. Three distinct supply lines operating at 350 bar (for HPDI), 100 bar (for Low Pressure Direct Injection), and 20 bar (for Port Fuel Injection) to accommodate diverse engine configurations. A separate ammonia delivery system ensures dual-fuel testing while addressing its specific chemical and safety needs. Safety remains a cornerstone of the facility's design due to hydrogen’s flammability and ammonia’s toxicity. Essential measures include a high-capacity ventilation, ATEX-rated electricals, real-time gas detection, inert-gas fire suppression, remote monitoring using CCTV, thermal imaging and acoustic sensors. The facility serves as a benchmark for hydrogen and ammonia ICE research in emerging markets, providing practical insights, and technical recommendations and guidance for aligned infrastructure development in support of a zero-carbon mobility future.