------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset: SONG 2 - Simulator of Network Growth version 2 2. Authors: David Levinson, Feng Xie, and Norah Montes de Oca 3. Author Contact: dlevinson@umn.edu 4. Date of data collection: 2006 5. Information about funding sources that supported the collection of the data: Minnesota Department of Transportation -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: Attribution-Noncommercial-ShareAlike 3.0 United States (http://creativecommons.org/licenses/by-nc-sa/3.0/us/) 2. Links to publications that cite or use the data: Levinson, David, Feng Xie, Norah Montes de Oca (2012) Forecasting and Evaluating Network Growth. Networks and Spatial Economics 12(2) 239-262. http://dx.doi.org/10.1007/s11067-009-9113-z http://hdl.handle.net/11299/180023 3. Recommended citation for the data: Xie, Feng; Levinson, David M. (2016). SONG 2 - Simulator of Network Growth version 2. Retrieved from the University of Minnesota Digital Conservancy, http://hdl.handle.net/11299/181334. --------------------- DATA & FILE OVERVIEW --------------------- SONG2.1.0, powered by NEXUS, is developed to predict the growth of the Twin Cities road network 20 years from now. This model has been calibrated. The calibration process starts from the 1990 network (Linkinfo_1990m.txt), exogenous 1990,1995,2000,2005 link capacities (read from Linkinfo_1990m, 1995m, 2000m, 2005m .txt, respectively), runs the travel demand model without investment and calibrates to match the station counts in 2005.The model starts from the 2005 network incorporating existing links, legacy links, and potential links (Linkinfo_2005.txt), with the flow pattern estimated from the last simulation period. To avoid confusions, code for calibration is not included. This package includes two versions respectively for Scenarios 1-6 (SONG_FINAL)a) and Scenario 7 (SONG_FINAL)b). The scenarios are developed in the paper "Forecasting and Evaluating Network Growth" by David Levinson, Feng Xie, and Norah Montes de Oca. The difference between the two versions lies in they use different initial network files ("Linkinfo_2005"), as Scenario 7 has an expanded choice set of potential new links. As a result, the initial network in SONG_FINAL_a comprises 20,468 links (20,380 existing links and 88 legacy links), while that in SONG_FINAL_b 35,224 links. TO RUN EITHER PACKAGE, import it as a project into Eclipse or other java platforms, find SONG.java which contains the main class, and run it (but not as an application). In the SONG.java file, the variable "scenarioID" can be changed to indicate another scenario. It is set to Scenario 1 as the default. -TGeneration.java includes estimated trip generation and trip attraction models. -TDistribution.java implements a doubly-constained trip distribution model. -DijkstrasAlgo.java includes the Dijkstra's algorithm for shortest path finding. -TAssignment.java includes Stochastic User Equilibrium traffic assignment. The original code is obtained in FORTRAN from Davis and Sanderson (2002). We translated it into java and made it more efficient. -Investment.java includes decision rules that vary by jurisdictions. Two major methods are included: the ranking() method scores road projects according to stated or revealed rules and ranks them according to the scores; the investing() method invests available budget in road projects according to their ranks and subject to costs and constraints. Please refer to "Forecasting and Evaluating Network Growth" for more details. (Feng Xie May 17, 2007) Running SONG may be computationally intensive, and may take an hour or more to finish. It runs until the 2035 iteration. SONG will create file outputs. In these "Linkinfo_XXXX" files, the output is as follows: The first five rows are: number of edges number of vertices number of centroids number of transportation analysis zones number of link attributes (subsequent columns) The columns are (numbered from 0 to 20): (according to DirectedGraph.java) public float link_info[][];//brackets:1-link index; 2-attribute index ///link attributes //0-link ID (from 1) //1-Origin node ID //2-Destination node ID //3-link type (functional class) //4-length //5-free flow speed //6-number of lanes //7-capacity //8-traffic flow (AM peak hour)veh/hour? //9-BPR travel time //10-County name //11-link status -1:not true road 0:existing link 1:legacy link //12-number of crashes //13-invested? //14-minimal distance to the nearest town center (in feet) //15-5 miles within St.Paul/Minneapolis CBD? //16-pavement quality index (pqi) //17-ownership 0-trunk highways 1-county roads 2-others //18-ecological region 0-no protection 1-should be protected //19-water 0-not across water land 1-across water land (by expanding one lane) //20-parks 0-not across parks 1-across water land (by expanding one lane) //for attribute 3 "link type" //Assignmet Groups //1 Metered Freeway //2 Unmetered Freeway //3 Metered Ramp //4 Unmetered Ramp //5 Divided Arterial //6 Undivided Arterial //7 Collector //8 HOV Lane //9 Centroid Connector //0 HOV Ramp //County name //1 Anoka //2 Carver //3 Dakota //4 Hennepin //5 Ramsey //6 Scott //7 Washington =========================== FILES FOR SONG_FINAL_A DijkstrasAlgo.class DirectedGraph$ReadANumber.class DirectedGraph.class FloatStack.class IntStack.class Investment.class SONG.class TAssignment.class TDistribution.class TGeneration.class DijkstrasAlgo.java DirectedGraph.java FloatStack.java IntStack.java Investment.java SONG.java TAssignment.java TDistribution.java TGeneration.java Text Files (unless otherwise noted, these files are loaded into the program to run it) --------- flow.txt Linkinfo_1990m.txt Linkinfo_1990n.txt Linkinfo_1995.txt Linkinfo_1995m.txt Linkinfo_2000.txt Linkinfo_2000m.txt Linkinfo_2005.txt Linkinfo_2005m.txt Linkinfo_2005n.txt Linkinfo_2010.txt - output of program Linkinfo_2015.txt - output of program Linkinfo_2020.txt - output of program Linkinfo_2025.txt - output of program Linkinfo_2030.txt - output of program Linkinfo_2035.txt - output of program link_mcd.txt mcd.txt ModifiedLinks.txt newLegacy.txt newNodeCoordinate.txt newNodeCoordinate_N.txt newPConstructionLinks1.txt newPConstructionLinks14826.txt newPConstructionLinks71851.txt NodeCoordinate.txt oldLinkinfo_2005.txt stations.txt stations1.txt TC_TAZ_1990.txt TC_TAZ_1990_old.txt TC_TAZ_2000.txt TC_TAZ_forecasted.txt TC_TAZ_forecasted1.txt Top200crash.txt ------------- FILES FOR SONG_FINAL_B DijkstrasAlgo.class DirectedGraph$ReadANumber.class DirectedGraph.class FloatStack.class IntStack.class Investment.class SONG.class TAssignment.class TDistribution.class TGeneration.class DijkstrasAlgo.java DirectedGraph.java FloatStack.java IntStack.java Investment.java SONG.java TAssignment.java TDistribution.java TGeneration.java Text Files (unless otherwise noted, these files are loaded into the program to run it) flow.txt Linkinfo_1990m.txt Linkinfo_1990n.txt Linkinfo_1995.txt Linkinfo_1995m.txt Linkinfo_2000.txt Linkinfo_2000m.txt Linkinfo_2005.txt Linkinfo_2005m.txt Linkinfo_2005n.txt Linkinfo_2005_1.txt Linkinfo_2010.txt - output of program Linkinfo_2015.txt - output of program Linkinfo_2020.txt - output of program Linkinfo_2025.txt - output of program Linkinfo_2030.txt - output of program Linkinfo_2035.txt - output of program link_mcd.txt mcd.txt ModifiedLinks.txt newLegacy.txt newNodeCoordinate.txt newNodeCoordinate_N.txt newPConstructionLinks1.txt newPConstructionLinks14826.txt newPConstructionLinks71851.txt NodeCoordinate.txt oldLinkinfo_2005.txt stations.txt stations1.txt TC_TAZ_1990.txt TC_TAZ_1990_old.txt TC_TAZ_2000.txt TC_TAZ_forecasted.txt TC_TAZ_forecasted1.txt Top200crash.txt -------------------------- METHODOLOGICAL INFORMATION -------------------------- Adapted from section 5 of Levinson, David, Feng Xie, Norah Montes de Oca (2012) Forecasting and Evaluating Network Growth. Networks and Spatial Economics 12(2) 239-262. http://dx.doi.org/10.1007/s11067-009-9113-z http://hdl.handle.net/11299/180023: "A range of seven scenarios has been constructed to examine how the timing and location of road expansion and new construction predicted by the simulation program SONG would be affected by varying: • Decision rules for expansion • Decision rules for new construction • Total budget • Budget split between expansion and new construction • Choice set of potential new links." In all the scenarios, the total budget available for road investment is estimated using the baseline budget model described in the last section, except in Scenario 4. The construction budget is split evenly between expansion of existing links and new construction, except in Scenario 5. Scenario 1 presents the baseline scenario. In Scenario 2, the most structured decision rules (those from Hennepin County) are applied for link expansion to every county. In Scenario 3, the least structured decision rules (those of Scott County) are applied for link expansion. For new construction, the revealed decision rules are used to prioritize links in all cases. In Scenario 4, budget alternatives are tested. Scenarios 4a- 4e respectively assume the construction budget allocated to each jurisdiction for each time interval is increased by 100%, 200% and 400%, and reduced by 10% and 25% (which is essentially equivalent to varying the budget split between construction and preservation). In Scenario 5, three-fourths of all dollars are allocated to new construction. When opportunities for new links are exhausted (all of the legacy links have been built), that budget is reallocated to link expansion. In contrast to Scenarios 1–5 that adopt stated decision rules for expansion, Scenarios 6 and 7 adopt revealed rules instead. While all of the scenarios take existing links as a baseline and consider them for expansion, the scenarios differ in what links to consider for new construction. Consistent with the first five scenarios, Scenario 6 uses only legacy links as links that are eligible for new construction, while Scenario 7 adds a set of potential links that have not been pre-specified on historical maps due to the relative scarcity of legacy links that are available for investment.