SONG 2 - Simulator of Network Growth version 2

Abstract

Software used in the project Beyond Business as Usual (MnDOT MN/RC-2006-36) This research, extending the Mn/DOT-funded project If They Come, Will You Build It, assesses the implications of existing trends on future network construction. It compares forecast networks (using models estimated on historical decisions developed with previous research) under alternative budget scenarios (trend, above trend, below trend), with networks constructed according to alternative sets of decision rules developed with Mn/DOT and Metropolitan Council staff. The comparison evaluates alternative futures using a set of performance measures to determine whether the network we would get in the absence of a change in policies (allowing historical policies to go forward) outperforms or underperforms the networks developed by applying suggested decision rules. This evaluation methodology enables new decision rules for network construction (building new links or widening existing links) to be tested. The research suggests a path beyond “business as usual”. This research incorporates results from the different scenarios tested. It presents the processes, approaches and development to encode historical decision rules. After analyzing flowcharts developed from the interviews of staff at different levels of government, if-then rules are generated for each jurisdiction. This research then describes the details and processes necessary to run the network forecasting models with various decision rules. Results for different scenarios are presented including adding additional constraints for the transportation network expansion and calibration process details. A comparison and analysis between scenarios is made in order to provide a final conclusion on what scenario will produce the greatest benefit for the Twin Cities Metropolitan Area Transportation Network.