TRB’s second Strategic Highway Research Program (SHRP 2) Report S2-L08-RW-1: Incorporation of Travel Time Reliability into the Highway Capacity Manual presents a summary of the work conducted during the development of two proposed new chapters for the Highway Capacity Manual 2010 (HCM2010). These chapters demonstrated how to apply travel time reliability methods to the analysis of freeways and urban streets.
The two proposed HCM chapters, numbers 36 and 37, introduce the concept of travel time reliability and offer new analytic methods. The prospective Chapter 36 for HCM2010 concerns freeway facilities and urban streets, and the prospective supplemental Chapter 37 elaborates on the methodologies and provides an example calculation. The chapters are proposed; they have not yet been accepted by TRB's Highway Capacity and Quality of Service (HCQS) Committee. The HCQS Committee has responsibility for approving the content of HCM2010.
SHRP 2 Reliability Project L08 has also released the FREEVAL and STREETVAL computational engines. The FREEVAL-RL computational engine employs a scenario generator that feeds the Freeway Highway Capacity Analysis methodology in order to generate a travel time distribution from which reliability metrics can be derived. The STREETVAL-RL computational engine employs a scenario generator that feeds the Urban Streets Highway Capacity Analysis methodology in order to generate a travel time distribution from which reliability metrics can be derived.
Software 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||12-13|
|Chapter 2 - Defining and Measuring Reliability||14-17|
|Chapter 3 - State of the Art and State of the Practice||18-23|
|Chapter 4 - Development of Freeway and Urban Streets Methodologies||24-36|
|Chapter 5 - Scenario Generator Development||37-79|
|Chapter 6 - Model Enhancements||80-106|
|Chapter 7 - Corridor Applications||107-110|
|Chapter 8 - Recommendations||111-119|
|Appendix A - FREEVAL User s Guide||122-141|
|Appendix B - STREETVAL User s Guide||142-168|
|Appendix C - Recurring Demand for Freeway Scenario Generator||169-174|
|Appendix D - Weather- and Incident-Related Crash Frequencies||175-192|
|Appendix E - Weather-Modeling Alternatives and Validation for the Freeway and Urban Street Scenario Generators||193-204|
|Appendix F - Incident Probabilities Estimation for Freeway Scenario Generator||205-215|
|Appendix G - Freeway Free-Flow Speed Adjustments for Weather, Incidents, and Work Zones||216-224|
|Appendix H - Default Factors for the Urban Streets Reliability Methodology||225-232|
|Appendix I - Example Problem: Existing Freeway Reliability||233-247|
|Appendix J - HCM Urban Streets Methodology Enhancements: Saturation Flow Rate Adjustment Factor for Work Zone Presence||248-263|
|Reliability Technical Coordinating Committee||264-264|
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