This book is a collection of the original peer-reviewed conference papers presented at the 2024 2nd International Conference on SmartRail, Traffic, and Transportation Engineering, organized by Chongqing Jiaotong University and Southwest Jiaotong University. The conference will be held on 25-27 October 2024 in Chongqing, China. It covers topics including SmartRail systems, autonomous vehicles, energy efficiency, sustainable transportation, big data in transportation, and machine learning. Speakers discussed innovative technologies and strategies to improve the efficiency, reliability, and safety of rail networks while exploring the opportunities and challenges of integrating autonomous vehicles into existing transportation networks. It provides valuable insights into the latest developments and trends in transportation engineering and technology, with a focus on electrification and sustainable transportation. It serves as a valuable resource for professionals, researchers, and students working in the field.