The introduction of new rolling stock from Stadler Rail, along with plans for updated signaling, a new operational control center, and platform screen doors (PSDs), signifies a crucial step towards enhancing passenger experience, safety, and operational efficiency. This modernization project not only addresses immediate operational needs but also lays the groundwork for the eventual transition to driverless operation, a significant advancement in modern railway technology. We will examine the challenges involved in this project, the technical specifications of the new rolling stock, and the strategic implications of the modernization efforts for the Glasgow Subway. The Unique Constraints of the Glasgow Subway The Glasgow Subway's age and unique design pose significant challenges. Its small tunnels and platforms severely restrict the size and design of rolling stock. This necessitated the custom design and manufacturing of the new trains by Stadler, precluding the use of off-the-shelf options.