Although Shanghai will participate in the annual World Car Free Day again this year, city officials aren’t asking the 1.46 million cars in the city to get off the roads. Drastically scaling back the city’s ambitions for tomorrow’s green event, which also happens to fall on Mid-Autumn Festival, only those living and going to the 2010 Expo area will be affected by the celebration, and the concept of “day” will be reduced to 12 hours.