Do you ever take shortcut way while you are driving to some place. My guess is that most of you do it, especially in Jakarta where traffic crowded oftenly. Surely, taking shortcut make you consume less time and gasoline. Most of the shortcut is not a main street. It could be a narrow street in the middle of public housing.
When traffic on a main street often get crowd someone will attempt find a shortcut way. And then when they find a shortcut, at the begining it give some credit because they drive more efficient. But then, the information is spreading symetricly and more people are taking shortcut. In the end that shortcut way become crowded. And that crowded way will spread into the another main street. That is clearly not a Pareto-Improvement. You can find numbers of public housing street easily in Jakarta transformed into crowded shortcut street and became main source of traffic jam.
Experienced traffic jam is the consequences of driving. Most people don't realize that because they only see problem in narrower stand point despite think about what result to others. Taking shortcut won't reduce traffic jam because it's only transfer crowd to some other places.
