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From page 1... ... 1Executive Summary Purpose and Need SHRP 2 Project C10A, Partnership to Develop an Integrated, Advanced Travel Demand Model and a Fine-Grained, Time-Sensitive Network, was undertaken to develop a dynamic, integrated model and to demonstrate its performance through validation tests and policy analyses. Key goals of the SHRP 2 C10A model system development effort include providing enhanced representation of travelers' sensitivities to price and incorporating findings from other SHRP 2 Capacity projects. Read the entire page →
From page 2... ... 2models typically incorporate accessibility measures that allow changes in network performance to influence demand generation. Agencies generally develop and apply activity-based models to include sensitivities to policies that may be challenging to represent in a traditional, trip-based models. Read the entire page →
From page 3... ... 3more information on network performance by detailed time of day, which can be used as input into travel model demand components. Features that distinguish dynamic network methods from static network approaches include the following: • DTA models incorporate more complete representations of transportation network attributes and configurations, including better representations of intersection controls such as signal synchronization and other advanced network control schemes. Read the entire page →
From page 4... ... 4have to be able to implement the model system in other regions without excessive costs or undue complexity. The resulting model system has the following features: • The model is scalable. Read the entire page →
From page 5... ... 5of trips or tours for individual household persons between specific activity locations (smaller than travel analysis zones but larger than individual parcels) to roadways, walkways, and transit modes on a second-by-second basis for a full travel day. Read the entire page →
From page 6... ... 6network detail -- specifically the number of links in the network. In the Burlington implementation, the TRANSIMS network is relatively coarse, and the small modeling area limits the number of network links. Read the entire page →
From page 7... ... 7model developed for this project seeks to address the following broad categories of policies and strategies: • Pricing policies; • Capacity enhancements; • Transportation system management (TSM) (and operations) Read the entire page →
From page 8... ... 8Planning Mode The planning application mode can be used when the analysis needs are expected to result in regional-scale changes in overall levels of travel demand or changes in regional travelers' destination, mode, or time-of-day choices but are not expected to be significantly affected by local-scale traffic dynamics. The planning mode integrates the DaySim demand model with the TRANSIMS supply model in an iterative feedback loop in which DaySim outputs estimates of travel demand at the level of individual minutes for routing within the TRANSIMS Router. Read the entire page →
From page 9... ... 9Planning Mode Applications The planning mode can be used when the policies or strategies being considered are expected to result in regional-scale changes in overall levels of travel demand or changes in regional travelers' destination, mode, or time-of-day choices, but are not expected to be significantly affected by local-scale traffic dynamics. The planning mode can be applied to the following primary policy and strategy analyses: • Pricing. Read the entire page →
From page 10... ... 10 Operations Mode The operations mode can be used when the analysis requires an assessment of the impacts of a policy or strategy on local traffic dynamics and when these improvements are not expected to result in changes in overall levels of travel demand or in destination, mode, or time-of-day choices. Operations Mode Configuration The distinguishing features of the operations mode are that it incorporates a full regional traffic microsimulation but does not include an iterative feedback loop in which microsimulatorbased network simulation impedance measures are fed back to DaySim. Read the entire page →
From page 11... ... 11 Planning + Operations Mode The planning + operations mode represents the fully integrated DaySim and TRANSIMS model system. In this application mode, the TRANSIMS Router and Microsimulator are used to perform a regional traffic microsimulation as part of every model system global iteration; microsimulation-based network impedance measures are fed back and used as input to DaySim. Read the entire page →
From page 12... ... 12 These models have potentially broad impacts on regional network levels of service, which could influence generation, distribution, mode choice, and route assignment. The use of regional traffic microsimulation within the integrated model provides a more robust platform for estimating these impacts. Read the entire page →
From page 13... ... 13 implementation is that the auxiliary demand is fixed for each forecast year. That is, although this demand varies by forecast year, it is not affected by changes in network impedances. Read the entire page →
From page 14... ... 14 to make informed decisions about how to modify model inputs to achieve the proper model sensitivity. Model users must also have a basic understanding of Python programming language to understand the overall model system flow, as well as robust data manipulation, statistical analysis, and geographic information system (GIS) Read the entire page →
From page 15... ... 15 Pricing Two types of pricing tests were evaluated as part of this effort. In the first, a number of scenarios were defined in which freeway tolls varied by time of day. Read the entire page →
From page 16... ... 16 showed more mixed results, with the signal progression producing better speeds in some corridor directions and worse speeds in other corridor directions. As others have noted, the sensitivity of DTA and traffic microsimulation models to these detailed inputs suggests distinct challenges when attempting to incorporate these assumptions into a forecasting mode, especially at a regional scale. Read the entire page →

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... 1Executive Summary Purpose and Need SHRP 2 Project C10A, Partnership to Develop an Integrated, Advanced Travel Demand Model and a Fine-Grained, Time-Sensitive Network, was undertaken to develop a dynamic, integrated model and to demonstrate its performance through validation tests and policy analyses. Key goals of the SHRP 2 C10A model system development effort include providing enhanced representation of travelers' sensitivities to price and incorporating findings from other SHRP 2 Capacity projects.