An anonymous reader quotes a report from Science Magazine: Eliminating carpool lanes could almost double drivers' traveling times, according to a new study. The findings come thanks to an unusual decision made by the government of Jakarta last year. Following allegations that drugged babies from poor households were being used as "jockeys," or passengers for hire, Indonesian lawmakers repealed the so-called three-in-one restriction. The law had required cars driving on the business district's main roads to carry at least three passengers during rush hours. To determine the impact on the city's drivers, Benjamin Olken, an economist at the Massachusetts Institute of Technology in Cambridge, and colleagues queried Google Maps for real-time driving-speed data before and after the new policy went into effect. Following the policy lift, travel delays, defined as the time it takes to travel 1 kilometer, increased by 46% in the morning and almost 90% in the evening, the team reports today in Science. But the most startling result is that phasing out the three-in-one policy led to worse traffic during times of the day and on roads where there had never been restrictions in place, Olken says. One possible explanation, he says, is that the three-in-one restriction led fewer people to drive into the city. "Maybe they carpooled, took public transit, or worked from home."