Fibre optic sensors (FOS) have emerged as a robust alternative to conventional vibration sensors due to their immunity to electromagnetic interference (EMI), high sensitivity, and suitability for harsh environments. This study presents a comparative analysis of single-mode (SM) and multi-mode (MM) fibre optic cables for vibration sensing, focusing on their performance in controlled and uncontrolled vehicular traffic scenarios. Distributed fibre optic sensing (DFOS) technology, specifically Phase Optical Time Domain Reflectometry (Φ-OTDR), was employed to measure vibrations. Results indicate that multi-mode fibres exhibit higher sensitivity to localized vibrations due to their larger core diameter and multiple propagation paths, while single-mode fibres offer superior performance over long distances with minimal attenuation. The study also highlights the advantages of multi-mode fibres in short-range applications, such as vehicular traffic monitoring, where high spatial resolution and multiplexing capabilities are critical. These findings provide valuable insights for selecting fibre optic cables based on specific vibration sensing requirements