The M77 Hydrogen project in Aberdeen, Scotland, has demonstrated promising results in driving carbon reduction through retrofitting vehicles with hydrogen technology. The project reported a 26% carbon reduction during road tests, emphasizing the significant carbon savings achievable through this approach. The simplicity and effectiveness of retrofitting existing vehicles with hydrogen technology have been highlighted, with vehicles having the option to switch to diesel when hydrogen is unavailable, reducing risks associated with hydrogen supply. However, challenges such as the cost of retrofit, limited availability of hydrogen refuellers, and hydrogen gas have been encountered. The project anticipates improvements in the hydrogen supply landscape in Scotland starting from 2026, which will enhance accessibility. Collaboration with partners like Aberdeen City Council and First Bus Aberdeen has been instrumental in sharing insights and experiences related to hydrogen refueling. Important steps such as information sharing under Non-Disclosure Agreements and aligning safety systems have been time-consuming but essential. Moving forward, the project plans to conduct quarterly lessons learned sessions and winter maintenance cycle tests, optimizing fuel displacement. Furthermore, they aim to secure funding to support the supply chain transition to hydrogen, promoting risk assessments, cost information sharing, and management plans. To ensure economic sustainability, the project intends to engage with the industry, build new connections, and advocate for competitive green hydrogen fuel rates. The proactive approach and collaboration of the M77 Hydrogen project position them as pioneers in the field, setting an example for others exploring hydrogen technology in construction.