This study investigates the preservation of the Iranian Transnational Railway as a World Heritage Site within the dual framework of development and conservation. Utilizing a descriptive-analytical method alongside interviews, observations, and document reviews, conservation and development strategies for the railway were prioritized. Questionnaire data were analyzed using SPSS software, with their statistical indicators and reliability assessed. The SWOT model was subsequently employed to identify strategies, and the Quantitative Strategic Planning Matrix (QSPM) was utilized for prioritization. SWOT matrix statements were weighted through interviews with a snowball-sampled group of 28 experts. Based on their feedback, 29 internal factors (16 strengths and 13 weaknesses) and 25 external factors (15 opportunities and 10 threats) were identified. Given the final scores of internal (3.23) and external (3.101) factors, proactive strategies (SO) were chosen as the preferred approach. The results indicate that a conservation-oriented approach in developing plans for the transnational railway is of utmost priority. Subsequent priorities include identifying and leveraging natural, historical, and cultural assets for revitalization, integrating World Heritage registration regulations and buffer zones into higher-level documents, establishing a national center for industrial and railway heritage documentation and research, proposing an investment and branding model for the railway, and assigning multifunctional roles to railway spaces. These findings can serve as a foundation for policymaking and macro-level planning to ensure the sustainable conservation and development of Iran's World Heritage railway.