text: In a program that's set to spread to other countries, millions of colombians hiked, biked, skated or took the buses to work. It was the third straight year cars have been banned with only buses and taxis permitted for the day without carsin this capital of 7 million. Of course the goal was to reduce smog and promote alternative transportation. The turnout was huge, despite gray clouds that dumped occasional rain showers on bogota. for the first time two other Colombian cities, cali and valledupar, joined the event. The day without cars is part of an improvment campain that began in Bogota in the mid-1990s.