Five mechanisms are examined by which traffic-controlled intersections can interact within a long-range traffic forecast, and the computational implications of each are explored. These mechanisms apply to networks that can adapt to changing travel behaviors over a long period of time. One mechanism relates to user-optimal equilibrium traffic assignment, which is a prerequisite for the remaining four: the chopping of traffic streams by signals, the smoothing of traffic streams by signs or meters, progressive signalization, and deployment of newly warranted traffic control devices. The inclusion of nodal interactions in traffic forecasts can substantially improve the precision of traffic forecasts but may require a very large increase in computational effort.