The type dimension of the Digital Tunnel Detector market is divided into four primary sub‑categories: handheld, portable, vehicle‑mounted, and robotic systems. Handheld detectors are low‑cost units used for spot checks and rapid assessments, contributing roughly 20 % of total market revenue due to their widespread adoption in small‑scale projects. Portable devices, featuring battery‑operated modules and modular sensors, address mid‑size operations and account for about 30 % of market size, driven by their balance of mobility and performance. Vehicle‑mounted detectors integrate high‑resolution scanning arrays onto construction or inspection vehicles, delivering extensive coverage for large tunnel networks; they represent the largest share at approximately 35 % of the market, reflecting capital‑intensive infrastructure investments. Robotic detectors, employing autonomous navigation and advanced data‑fusion algorithms, are emerging in high‑risk environments and currently hold around 15 % of the market, a share expected to grow as automation gains traction. Collectively, these type segments shape the overall Digital Tunnel Detector segmentation landscape and inform strategic resource allocation.