Thanks for your comments. The on-line Trucking Decision Aid concept applies primarily to independent truckers (that own their vehicles), or the dispatchers of trucking firms with a small fleet, and only if there is time flexibility (e.g., a 12 to 24 hour window within which a load must be delivered). The planning decisions are when to depart, whether to accept a load and how to much to charge. Roughly, for a semi tractor-trailer traveling at legal highway speed (e.g., 65 mph), if the headwind speed, in line with the road, is 20 mph (85 mph relative wind speed), the fuel consumption per mile roughly doubles. If the relative wind to the moving truck is 15-degrees off-axis, the coefficient-of-drag roughly doubles from the in-line case. I've spoken to some independent truckers at truck stops in the United States. They may not know the engineering calculations, but, from their on-road experience, they know what a 20 mph headwind can do to their bottom line (cost of diesel fuel). One trucker came up to buy a cup of coffee as he paid for the cost to refuel his big rig, and threw his hat down on the counter with, "Not going to make anything today. Bucked strong headwinds all the way." Trucking operations do have some time flexibility. A close cousin to strong head winds is hazardous weather. For example, if a large portion of the highway is covered by glaze ice that is forecast to melt 8 hours later, what would the trucker decide to do? If he has to feed his family, he may decide to take the increased risk and leave early, which brings in highway safety.
Posts made by OldWxGuy
RE: Trucking Decision Aid
Trucking Decision Aid
Re: Surface Wind Forecasts for Long-Haul Trucking Operations
If I had the software programming skills, I would have set up a website with a trucking decision aid (TDA) interface, where a trucker (or trucking dispatcher) could enter departure and delivery points, creating a tabular display of equivalent average head/tail wind for the route as a function of departure time in hourly increments. The programmers at Windy have the necessary skills. I envision a semi-truck logo that when clicked a TDA would be displayed. In addition to how forecast weather information is displayed at Windy.com, this would be a operationally tailored application.
Surface Wind Forecasts for Long-Haul Trucking Operations
Atmospheric wind-field forecasts and oceanographic surface-wind/surface-current/sea-state forecasts are already being used for aircraft and ship routing/scheduling to achieve minimum time or minimum fuel for transportation between two points. Compared to aircraft and ship operations, truck routes are constrained to the highway system. However, depending on load urgency, there is flexibility in truck scheduling to avoid headwinds or to take advantage of tailwinds. Additionally, there are business-related decisions associated with foreknowledge of route-tailored surface winds: i.e., whether to accept a load and what to charge to transport it. The most optimum decisions can be made when surface winds are forecast to be strong and changing over the planned truck route. Pertinent is that relative wind over a moving truck affects fuel-consumption (and greenhouse gas emissions) as the square of the relative velocity, and relative wind (yaw) angle.
Windy already has real-time access to the North American Mesoscale (NAM) model with sufficient 5-kilometer grid resolution. Integration (interpolation) with the national highway database, time-phased according to speed limits in the database, using a vehicular wind drag model, can be used to calculate equivalent head/tail wind over a planned route for a list of truck departure times. The following, readily available information can be used to produce an interactive, Web-based, tabular, trucking decision aid.
- Department of Transportation National Highway Planning Network (NHPN) Geographical Information System (GIS) database (line segment features) for current and planned highways across the United States.
- Department of Energy Heavy Vehicle Aerodynamic Drag model to calculate vehicular (tractor/trailer) wind-induced drag as a function of truck highway speed and wind speed/direction relative to the highway.