Development and Application of a Framework to Classify and Mitigate Truck Bottlenecks to Improve Freight Mobility

This paper presents a framework to classify and mitigate roadway bottlenecks and that is designed to improve freight mobility. This is in recognition that roadway operations for trucks are under studied, truck-only bottlenecks are often not identified and freight-specific problem areas are therefore often overlooked. The framework uses four-steps:

Step 1: identifies and locates the roadway sections where vehicle travel time is in excess of what would normally occur.

Step 2: made possible by increasingly available truck probe data, identifies bottlenecks for all vehicles or for trucks only. This is necessary to identify bottlenecks that notably impact freight mobility and might not be identified by car-based approaches.

Step 3: classifies bottlenecks as travel speed-based or process-based. This selects the mitigation treatments as mainly due to operational or roadway limitations.

Step 4: which is the core of the paper, supports the mitigation process by determining the cause of the bottleneck. The bottlenecks are identified as due to congestion, limitations where roadway design slows all vehicles, or where a truck’s size or weight can slow vehicles (such as tight curves or bridge restrictions).

The paper present a review of specific roadway attributes that limit a truck’s mobility and is used to suggest mitigation. The framework is demonstrated using a case study. The framework is designed to be applied by planning and infrastructure agencies who want to locate and address freight bottlenecks in a systematic manner using available resources as well as by researchers interested in linking roadway attributes to truck mobility.