We've all had that feeling of sitting in traffic, staring at the carpool lane that we can't use because there isn't anyone else in the car. It feels like a waste of a lane, but a new study shows that removing it could make things much worse.
A new study published in Science examines what happened when Jakarta, Indonesia, removed a "three-in-one" restriction that required every vehicle in Jakarta's business district to carry at least three passengers during rush hour. The change came after news broke that babies from poor households were being used to fill cars during these restrictions.
Using real-time traffic data from Google, researchers found that the time it took to commute 1 kilometer went up 46 percent during the morning rush hour, and nearly 90 percent in the evening. That's almost half the speeds experienced prior to lifting the restriction.
Even stranger, researchers found that removing this carpool-lane-like restriction actually made traffic worse on roads that never had such a restriction, and it also worsened traffic during other times of the day. Researchers offered explanations for this phenomenon, but there's no official reason as to why or how that happened.
The main takeaway from the whole piece is pretty straightforward -- carpool lanes are useful, even though drivers of single-occupant vehicles might be miffed about it. It's a vital method for helping reduce urban congestion, especially in developing countries, where drivers may have a harder time paying congestion taxes. So, the next time you see a carpool lane moving much faster than your own, don't get mad at it -- be happy that it's there.