TRB's National Cooperative Highway Research Program (NCHRP) Report 707: Guidelines on the Use of Auxiliary Through Lanes at Signalized Intersections provides guidelines to help in the justification, design, and analysis of auxiliary through lanes (ATLs) at signalized intersections.
ATLs are lanes for through movements that begin upstream of a signalized intersection and end downstream of the intersection. ATLs are potentially a moderate-cost approach to increase intersection and overall corridor capacity.
A report that describes the research related to the development of NCHRP Report 707 has been released as NCHRP Web-Only Document 178: Assessment of Auxiliary Through Lanes at Signalized Intersections.
A spreadsheet-based computational engine is also available online.
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