Beijing's dirty air showed dramatic improvement Wednesday. City officials indicate that curbs on cars and factories are having the desired effect in cleaning up the air for the start of the Olympics at the end of next week. On July 20 authorities began implementing a series of drastic measures to improve air quality ahead of the game. The city pulled half the city's 3.3 million vehicles off the roads, stopped most construction and closed some factories in the capital and surrounding provinces. In recent days high temperatures and a thick, grayish haze reduced Beijing's visibility. However, a tropical storm that hit southeastern China earlier this week brought strong wind and some rain on Tuesday. The effect of the storm was to lower temperatures and clear some of the pollution from the skies. Some U.S. athletes are considering wearing masks. New Zealand's athletes have been issued face masks with team equipment. Team managers have advised athletes to wear masks around the Olympic village but not during competition.