Statewide and Megaregional Travel Forecasting Models: Freight and Passenger (2017) / Chapter Skim
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20 chapter three Survey of exiSting Practice Statewide modeling is becoming mainstream in the United States.
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21 FIGURE 5 Frequency of travel demand model types for person travel (multiple answers allowed)
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22 Hawaii as an island state does not operate a statewide model. Individual models are implemented for the islands of Kauai, Maui, Oahu, and Hawaii, covering more than 99% of the state's population.
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23 or the number of trips attracted) , the distance to every other zone, and possibly other factors that may affect destination choice.
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24 Eight models account for non-motorized travel as well. Often, the resolution in statewide models is too coarse to reasonably account for this mode.
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25 after those periods. However, more time intervals increase the computational burden and the need to model departure time shifts.
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26 congested travel times may be reached. The concept is shown for traditional four-step models in Figure 14.
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27 Long-distance models tend to be implemented in larger states by area, as shown in Figure 17. However, some large states, such as California or Florida, do not operate long-distance models, while other smaller states, such as Maryland, do run long-distance models.
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28 FIGURE 18 Travel demand generation rates for person long-distance travel (multiple answers allowed)
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29 only 4.1% of all registered vehicles and only 2.5% of all new vehicle sales in the United States (BEA 2016)
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30 are uncommon in statewide models. The heterogeneous travel behavior of trucks (depending, among other factors, on truck type and commodities carried)
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31 less common in states in the northern parts of the United States. The Interstate 10 corridor and possibly the I-65 corridor (though Tennessee did not participate in this survey)
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32 and unknown modes. One other mode was mentioned by Utah, where truck-rail intermodal represents a separate mode.
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33 Respondents in the nine states who selected "Other forecast" mentioned that they: • Prepare their own forecast, • Use the REMI economic forecasting model, • Derive population growth forecasts from Longitudinal Employment Household Dynamics and Woods & Poole population trends, and • Work with universities or local consultants to generate forecasts. The agency that operates the transportation model creates its forecast of socioeconomic data in only six states (or 18% of those that have statewide models)
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34 forecasted using transportation models. The location choices of households, businesses, and developers, in turn, influence the origins and destinations of travel demand calculated in the transportation model.
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35 analyze the impact on water quality have been developed (see chapter seven, "Chesapeake Bay Megaregion Model" and Baker et al.
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36 combination with their own GHG model (GreenStep) , and Kentucky uses both MOVES and its predecessor, MOBILE.
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37 3.1.7 resources Agencies that operate statewide models were asked about the resources they have invested in model development and application. The first question asked for the number of full-time equivalent employees.
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38 For model application, the percentages are almost completely reversed, as shown in Figure 38. In-house and partner agencies on average conduct 60% of the model application work.
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39 refined by four different scientists. A pretest was conducted that helped fine-tune contents.
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40 the simpler model would always be preferred as it limits the risk of model inconsistencies. As Albert Einstein is said to have noted, "A model should be as simple as possible, yet no simpler." Moreover, the temporal, spatial, and behavioral resolutions found in many state-of-the-art urban models would be prohibitively costly if extended to cover an entire state.
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