BACKGROUND
Bottlenecks, situations in which the performance or capacity of an entire system is severely limited by a single component, delay large numbers of truck freight shipments and negatively impact the nation’s economy and productivity. As the domestic freight ton-miles traveled by truck is expected to increase by 53% in 30 years, reducing truck bottlenecks will be a major solution for increasing truck freight efficiency and reliability. In addition, Moving Ahead for Progress in the 21st Century (MAP-21) requires states to report on how they are addressing freight bottlenecks. To address this issue, national, state, and regional transportation agencies need sound methodologies to define, identify, quantitatively measure, and mitigate truck bottlenecks to justify the mitigation of the bottlenecks. Without such methodologies, transportation agencies will be unable to address truck freight bottleneck issues systematically. Fixing one location may simply shift the bottleneck to another location on the network, with no improvement to the overall corridor performance. Without defining and describing bottlenecks by categories based on causal and contributing factors, decision makers will be unable to develop cost-effective solutions to address different types of truck freight bottlenecks.
Several national and regional studies have identified and quantified truck bottlenecks, including the FHWA Freight Bottleneck Study, FHWA Freight Performance Measure Program, and INRIX Traffic Scorecard. However, these studies either defined truck bottlenecks as congestion related or did not develop a comprehensive classification of truck bottleneck categories. In addition, the measures to quantify bottleneck severity were developed to capture congestion impacts or delays and are unable to measure the impact of other types of bottlenecks, such as vehicle size and weight restrictions, intermittent closures, roadway geometrics, height restrictions, weather restrictions, hazardous materials routing, and truck bans. There is a need for a comprehensive classification of truck freight bottleneck types that provides a standard approach for state DOTs, MPOs, and other practitioners to define truck freight bottlenecks and quantify their impacts.
OBJECTIVE
The objective of this research is to develop a guide that (1) classifies truck freight bottleneck categories based on causal and contributing factors (e.g., roadway geometrics, regulatory constraints, traffic controls, weather, and border crossings); (2) describes quantitative measures for each truck freight bottleneck category to determine bottleneck severity, impact, and ranking; (3) develops a scalable methodology for systematically identifying truck freight bottlenecks and evaluating their impact on local, regional, and national network performance; and (4) describes a range of options for solving or mitigating truck freight bottlenecks.
Accomplishment of the project objective will require at least the following tasks.
TASKS
(1). Conduct a review of current practices and measures used to identify truck freight bottlenecks; typologies used to classify the types of truck freight bottlenecks; criteria used to evaluate the types of bottlenecks; and steps that have been taken to mitigate various types of bottlenecks. (2). Based on the results of Task 1, identify gaps, conflicts, and overlaps among current practices. (3). Prepare a technical memorandum providing the results of Tasks 1 and 2.(4). Conduct a conference call with NCHRP to discuss the Task 3 technical memorandum. (5). Develop a classification of truck freight bottleneck categories based on causal and contributing factors (e.g., roadway geometrics, regulatory constraints, traffic controls, weather, hazardous materials routing, and border crossings). Develop methods (including data and tools as appropriate) for quantitatively measuring truck freight bottlenecks within each of the categories. Develop a scalable methodology for systematically identifying truck freight bottlenecks and evaluating their impacts on local, regional, and national network performance. Develop a range of options for solving or mitigating truck freight bottlenecks for each identified category.(6). Within 6 months, prepare an interim report that provides the results of Tasks 1 through 5, a detailed outline of the guide, and a list of 25 candidate participants (e.g., state DOTs, MPOs, other jurisdictions, shippers, trucking companies) for the Task 8 workshop. (7). Prepare the guide that (1) classifies truck freight bottleneck categories based on causal and contributing factors (e.g., roadway geometrics, regulatory constraints, traffic controls, weather, and border crossings); (2) describes quantitative measures for each truck freight bottleneck category to determine bottleneck severity, impact, and ranking; (3) develops a scalable methodology for systematically identifying truck freight bottlenecks and evaluating their impact on local, regional, and national network performance; and (4) describes a range of options for solving or mitigating truck freight bottlenecks. (8). Conduct a 1.5-day workshop at the National Academies Beckman Center in Irvine, California (including invited attendees and panel members) to demonstrate the applicability of the guide to its primary users. NCHRP will be responsible for all meeting and hotel logistics, travel expenses for participants, confirmation of attendance, and expenses related to meals and lodging. The contractor will be responsible for covering all other costs, such as their own travel expenses, invitations, agenda, electronic presentations, and handout materials. (9). Based on the results of the workshop, revise the guide as needed. (10). Prepare final deliverables that include: (1) a final report documenting the entire research effort and (2) the revised guide.
