"车顶安全把手" can be translated as "roof safety handle" or "overhead safety grab handle" in English.
"Roof safety handle" directly refers to the handle located on the roof of a vehicle for safety purposes.
"Overhead safety grab handle" provides a more detailed description, indicating that the handle is positioned overhead (i.e., on the roof) and is meant for grabbing to ensure safety.
Both translations are acceptable, and the choice between them may depend on the specific context or preference.