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Highway Capacity Manual Methodologies for Corridors Involving Freeways and Surface Streets

项目名称：	Highway Capacity Manual Methodologies for Corridors Involving Freeways and Surface Streets
摘要：	Highway agencies and municipalities are increasingly interested in corridor-level analysis, creating a need for accurate methods to measure and predict traffic operations across multiple facilities in a corridor. Recent editions of the Highway Capacity Manual (HCM) have improved analysts� ability to consider the disparate elements of "Freeway Facilities" (Chapter 10) and "Urban Streets" (Chapter 16) in their respective system contexts, but the HCM is generally silent on the interactions between these two major facility classes. In fact, the structure of the HCM tacitly inhibits analyses of these interactions by using different performance and service measure approaches. This artificial separation does not reflect motorists� daily experiences, which often involve transitioning from one facility type to another on any given trip. The lack of a methodology to analyze the operational characteristics of these transitions could result in designs that fail to address certain congestion problems. Interactions between freeway and surface street facilities typically take place at interchanges. At the surface street end of a freeway off-ramp, an oversaturated intersection can cause queues that may back up to and affect operations on the freeway mainline. Conversely, congestion at the freeway end of an on-ramp can result in queues extending upstream towards the intersection that may affect operation on the surface street. These interactions are not explicitly accounted for in the HCM. Proper consideration of these effects is important in evaluating alternative designs, evaluating active transportation and demand management (ATDM) and other operational strategies, and estimating system performance measures such as travel time reliability. The upcoming 6th edition of the HCM begins to address ATDM and travel time reliability, though most of the material is for freeway facilities. Many microscopic simulation software packages are designed to allow analysis of freeways and surface streets simultaneously, and the current state of the practice is to use simulation for such analysis. However, unlike many of the other elements of microscopic simulation, freeway--surface street interactions have no deterministic analog either in the literature, in general, or in the HCM, in particular, and thus lack the performance benchmark that the HCM is able to provide. Enhancing the ability of the HCM to address these corridors will provide analysts with another tool that for many situations will be easier to use. The objective of this research is to develop material for the HCM that allows the analysis of corridors that include freeways and surface streets (e.g., Exhibit 2-1 of the HCM, 6th Edition). The research should emphasize the use of field data (existing and new) for the development and validation of methodologies. The HCM material should be based on the 6th edition of the HCM and include: (1) Performance and service measures for trips within corridors that use both the freeway and surface street facilities (urban streets for urban areas; multilane highways and two-lane highways for rural areas). All affected modes should be considered. (2) An analysis framework, primarily for planning and design purposes, that can be used to estimate the performance measures for alternative designs (including active traffic and demand management and other operational strategies) based largely on 6th edition HCM methodologies. (3) Adjustment factors and recommended modifications for HCM methodologies based on interactions between the freeway and surface street methodologies (e.g., queue spillback from ramp meters and ramp terminals, effects of platooned on-ramp vehicles). (4) Guidance on scoping the analysis, including spatial and temporal boundaries for the analysis corridor. (5) Limitations of the framework and methodologies. Conditions under which other analytical approaches would be more practical should be described. The capability of the framework and methodologies to accommodate demand shifts should be discussed. (6) Data requirements for the use of the framework and methodologies, including techniques for collecting the data. (7) Information on how traffic simulation, dynamic traffic assignment, and other alternative analysis approaches can complement the HCM material including comparing, integrating, and interpreting the analysis results. (8) Guidance on incorporating probe vehicle, crowd-sourced data, and other emerging data sources into the generation of performance measures and validation of analysis results. (9) Example problems illustrating use of the framework and methodologies.
状态：	Active
资金：	800000
资助组织：	National Cooperative Highway Research Program
项目负责人：	Derr, B Ray
执行机构：	University of Florida Transportation Institute
主要研究人员：	Elefteriadou, Lily
开始时间：	20160818
预计完成日期：	20200517
实际结束时间：	0