I hate trying to school ignorant people.  I'll add this quote, though:

The Science of Traffic.
More lanes often means more traffic because people like to go places, as long as the threat of bumper to bumper doesn't dissuade them. Widening a highway may ease the pressure, but only until everyone learns of the quick, new route about town.
Civil engineers liken traffic to a gas: It expands to fill the space provided. As civil engineer and sustainability advocate Charles Marohn so eloquently put it, “Trying to solve congestion by making roadways wider is like trying to solve obesity by buying bigger pants."