On highways, platoons of semi-trucks are a common phenomenon. By maintaining a
small headway, these platoons can effectively reduce air resistance, thereby
improving fuel efficiency and reducing carbon emissions. However, this driving
mode is also accompanied by many safety and operational risks, such as increased
risk of rear-end collisions, reduced driving comfort, and susceptibility to
interference from other vehicles outside the platoon. Therefore, behavioral
analysis and evaluation of semi-truck platoons naturally formed in real traffic
environments are of great significance for improving their driving safety,
comfort and stability. This study focuses on the headway characteristics of
semi-truck platoons, analyzes their headway distribution, headway gap and
braking response behavior, and then proposes a safe headway threshold for
emergency braking to effectively reduce the probability of rear-end collisions.
In addition, the study also defines an optimal headway range to reduce the
possibility of external vehicle insertion, thereby improving the overall
stability and driving experience of the platoon. Based on this, this paper
constructs a semi-truck platoon model with safety as the core, and verifies it
with actual traffic data, revealing the behavioral characteristics of naturally
formed semi-truck platoons in terms of safety headways, optimal headways, and
platoon distributions. The research results not only provide theoretical support
for improving the safety and stable operation of naturally formed truck
platoons, but also provide technical reference for the deployment and operation
of future connected and automated truck (CAT) platoons in real road
environments, helping the freight industry to develop in a more efficient and
sustainable direction.