1-2.2: Traffic Signal Plans to Decongest Street Grids

Abstract

This project, a companion to Project 1-2 Supply Side Management of Auto Traffic, will entail synchronizing green phases across neighboring traffic signals to the backward waves that propagate through queues. The goal is to ensure that green phases are displayed only after queues recede on street segments downstream. In this way, traffic movements are not blocked when they receive green signals. Intersections will be added or removed from this coordination scheme as queues expand or contract over a rush. Unlike previous efforts in this realm, the present research will focus on backward signal progression on two-way streets and integrating this backward scheme with other signal-timing strategies used elsewhere in a city. As regards the latter focus, the research team will pursue a strategy in which intersections inside a congested downtown district are synchronized in reverse fashion, while intersections in outlying neighborhoods are coordinated in such ways as to feed traffic to the downtown district at the highest rates feasible.