This is the 288th most frequent Chinese word.
交通
Transportation; traffic.
In this sentence, the word "交通" refers to traffic conditions in a city or area, indicating the flow and management of vehicles and pedestrians.
这个城市的交通状况不好，常常堵车。
The traffic conditions in this city are bad, and traffic jams are frequent.
In this context, "交通" combined with "工具" refers to modes or means of transportation, specifically the subway.
地铁是一种快捷的交通工具。
The subway is a fast means of transportation.
Here, "交通" is used to emphasize safety in relation to traffic, including vehicles and pedestrians.