Air Quality Considerations in the Design of Intermittent Cut-and-Cover Highway Tunnels

摘要

The document summarizes the experimental studies carried out for predicting air quality in and about passively-ventilated (no mechanical ventilation), intermittently-covered highways (such as cut-and-cover freeways). The information is presented in a handbook manner so it can readily be used by highway planners and designers to estimate the distribution of the concentrations of vehicle exhaust for many types of multiple-tunnel highway system designs. The results of the report can be used to lower the acquistion, construction, and/or operation costs of freeways in central business districts by making more feasible the use of intermittent, unventilated, multiple tunnels as opposed to ventilated tunnels or open cuts. All this can be accomplished while minimizing: adverse effects of a freeway dividing and/or interrupting the established traffic/pedestrian patterns of an urban area; loss of the tax base.