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.
Spreadsheet Disclaimer - This software is offered as is, without warranty or promise of support of any kind either expressed or implied. Under no circumstance will the National Academy of Sciences or the Transportation Research Board (collectively "TRB') be liable for any loss or damage caused by the installation or operation of this product. TRB makes no representation or warranty of any kind, expressed or implied, in fact or in law, including without limitation, the warranty of merchantability or the warranty of fitness for a particular purpose, and shall not in any case be liable for any consequential or special damages.
Table of Contents
|Chapter 1 - Introduction||1-1|
|Limitations of the Guidelines||2-2|
|Organization of Guidelines||3-4|
|Recommended Resource Documents||5-5|
|Geometric and Traffic Design||9-9|
|Chapter 3 - Operational Analysis||14-14|
|Data Collection Requirements||22-22|
|ATL Volume Estimation||23-25|
|Numerical Illustration of ATL Volume Prediction||26-27|
|Observed Safety Performance||29-33|
|Safety Evaluation Considerations||34-35|
|Chapter 6 - Sample Application||54-55|
|ATL Application Example Description||56-56|
|Preliminary Horizontal Geometric Design||61-62|
|Chapter 7 - References||65-65|
|Appendix A - A Simulation-Based Approach to ATL Evaluation||66-74|
|Appendix B - Computational Engine||75-77|
|Appendix C - Estimation of Design Lengths of ATL Components||78-83|
|Abbreviations used without definitions in TRB publications||84-84|