Most passengers would not want to travel to infected countries and therefore traffic volumes would be low.

大多数乘客都不想去感染国家旅行，因此交通承载量将很低。

OK, let's make it better: " I will attempt to show that investment in public transport can help to reduce traffic volume."

好，让我们更进一步：我将要写出可以减少交通拥堵状况的公共投入。

By prioritizing public transportation, cities can reduce traffic volume, decrease air pollution, and provide more accessible and affordable transportation options for residents.

通过优先考虑公共交通, 城市可以减少交通量, 减少空气污染, 并为居民提供更方便、更实惠的交通选择。