Present participle as an adverbial: In "adhering to safety protocols", the present participle phrase "adhering to" is used at the beginning of the sentence, increasing the complexity and richness of the sentence.
Passive voice: In "must comply with the guidelines established", passive voice is used to indicate that the "guidelines" are established by the "transport authority", making the sentence more formal and complex.
Conditional sentence pattern: In "being vigilant about unusual activities, such as suspicious behavior or unattended items", a conditional sentence pattern is used to describe the actions that should be taken in specific situations, increasing the complexity of the sentence.
Gerund phrase as subject: In "reporting them promptly", "reporting" is used as a gerund phrase serving as the subject, expressing continuous action.