>>1685002(cont). I should correct this, when a roadway becomes saturated (reaches maximum capacity), it'll slow down and congest. So it's not just the unmet demand that will get slowed, it's basically everyone on the roadway at the time.
Induced demand, as alluded to in this thread and by a crude comparison to a boreal forest highway, is the concept that adding more capacity to a roadway may not actually reduce congestion. Let's say you have a highway that is already saturated, meaning demand has outpaced capacity and the highway is always congested. Because of this congestion, there is a portion of drivers who choose not to use the highway in its current form. They know it's congested, thus they either avoid it or choose not to drive or perhaps are currently using an alternative means. Now, you add a new lane to the highway, increasing capacity. People who did not previously utilize the congested highway may now decide to because it is less congested with the additional lane. Suddenly, demand has increased and the highway is once again at capacity. The Wikipedia page on this is worth a read. It has been observed and studied multiple times and is not a buzzword despite the naysayers.
