Not only did we observe a loss in benefits from the new Paseo del Norte bridge on other bridges' traffic volumes, but that traffic around the new Paseo del Norte Bridge actually increased at a faster rate as a result of the new bridge. Traffic has not declined as a result of the new bridge, but instead has increased. The new bridge has generated new traffic. Half of the new road capacity was occupied by driving that would not have taken place if the additional road space had not been built. Todd Litman of the Victoria Transport Policy Institute divides generated traffic into two types.
Diverted traffic is existing trips reallocated to a different time, route, or destination.
According to Litman, traffic congestion maintains an equilibrium when traffic levels reach a point where the existing road can no longer handle an increase in automobile trips during peak periods. New road facilities attract drivers who now take additional trips and longer trips to further destinations that they would not have taken under previous congested conditions. Also, drivers hoping to save time on the new route over previous routes or other slower modes of travel create generated traffic. Several studies have documented the fact that new roads encourage more cars and more trips made by drivers. Newly widened I-287 in New Jersey was congested with traffic only two months after construction was completed.