OBJECTIVE
The objective of the research was to develop improved, nationally accepted capacity and level of service techniques suitable for incorporation into the HCM that (1) improve transportation agencies’ abilities to plan, design, manage, and operate streets and highways to serve trucks and (2) better evaluate the effects of trucks on other modes of transportation and vice versa. Techniques are needed for uninterrupted and interrupted flow facilities in both rural and urban conditions.
STATUS
BACKGROUND
In 2009, trucks moved 10.9 billion tons of freight; by 2040 trucks are expected to move 18.4 billion tons of freight (Freight Facts and Figures 2010, FHWA). The growth in trucking can be attributed to a number of factors, including changes in population and employment; the modal shift of freight to trucks from other modes; and changes in the economy and business practices that affect the freight transportation system. Transportation decisions should facilitate and account for freight flows, but analysts lack the tools needed to evaluate them.
The Highway Capacity Manual (HCM) is a fundamental reference for the operational analysis of streets and highways. While the 1950 HCM was focused on automobile traffic, later editions have incorporated research that has been conducted on pedestrians, bicyclists, and transit users. The 2010 HCM, however, largely considers trucks only as they impact other travelers. Incorporation of truck analysis into the HCM will help transportation agencies address the freight and highway needs of their community, region, state, and nation
TASKS
Task 1. Analyze, describe, and critique pertinent domestic and international research on the basis of applicability, conclusiveness of findings, and usefulness for the analysis of truck operations on streets and highways. Document how trucks are addressed in the HCM 2010 and identify deficiencies. Review the HCM equivalents used in other countries to identify techniques and material that could be useful additions to truck application of the HCM 2010.
Task 2. Interview or conduct focus groups of representative state DOT and MPO personnel and other practitioners to determine how the HCM could be appropriately used in the analysis of truck operations on streets and highways (e.g., freight corridors and connectors; rural mountainous freeways and multilane highways; and urban streets). Identify deficiencies in the HCM related to truck analysis. Identify and describe methods that practitioners have used to successfully adapt the HCM methodologies to meet their needs in analyzing truck traffic. Describe how the results of truck analysis should be considered in the planning and prioritization of projects and the performance measurement of the system.
Task 3. Interview or conduct focus groups of shippers, carriers, and logistical consultants to determine the critical performance measures that affect their perception of the operation of streets and highways. Examine the suitability of applying the automobile level of service/quality of service framework to trucks. Explore methods of using performance measures that could be produced by the HCM methodologies to roughly estimate the economic value of freight movements to the community.
Task 4. Develop a classification scheme for trucks that is consistent with national schemes but suitable for inclusion in the HCM. Performance characteristics (e.g., acceleration, deceleration, weight, length, emissions, and operational constraints) for each class should be described in both laden and unladen states.
Task 5. Develop a conceptual framework for analyzing truck operations in the HCM. Identify and describe specific data collection and analysis efforts needed to develop the framework and methodologies within the framework. Catalog the input data that is likely to be needed for the analysis methodologies included in the framework and describe sources for that data.
Task 6. Submit an interim report summarizing the work done in Tasks 1 through 5 and presenting an updated work plan for the remaining tasks. Meet with the NCFRP project oversight panel for the review and approval of the interim report.
Task 7. Carry out data collection and analysis efforts and develop the framework and methodologies as identified in Task 5 and approved or modified at the interim meeting.
Task 8. Develop case studies demonstrating how the framework and methodologies developed in Task 7 will address typical applications identified in Task 2. Highlight improved capabilities over existing methods.
Task 9. Develop a supplemental chapter to the HCM 2010 that fully presents the framework and methodologies. The limitations should be described as well as any special considerations such as sensitivity analysis. The chapter should discuss appropriate uses of default values. This chapter should be suitable for publication in Volume 4 of the HCM 2010.
Task 10. Develop a final report that documents the entire research effort and includes the Task 9 chapter as a stand-alone appendix. If appropriate, the report should describe how the material in that chapter could be incorporated into a future edition of the HCM.
