RELATED RESOUCES:
The purpose of this lab session is to perform travel demand modeling and logistics analysis using TransCAD. First, you need to download the demo files (TransCAD_demo.zip) from Blackboard. Then, open the TransCAD 8.0 (Academic 64-bit).
The goal of trip generation is to predict the number of trips that are generated by and attracted to each zone in a study area. This is only concerned with the number of trips that start and end in each zone, and not with making connections between origins and destinations of trips.
There are three primary tools that are used in modeling trip production:
Cross-Classification:
Cross-classification methods separate the population in an urban area into relatively homogeneous groups based on certain socio-economic characteristics. Then, average trip production rates per household or individual are empirically estimated for each classification. This creates a lookup table that may be used to forecast trip productions.
Regression Models:
Two types of regressions are commonly used. The first uses data aggregated at the zonal level, with average number of trips per household in the zone as the dependent variable and average zonal characteristics as the explanatory variables. The second uses disaggregated data at the household or individual level, with the number of trips made by a household or individual as the dependent variable and the household and personal characteristics as the explanatory variables.
Discrete Choice Models:
Discrete choice models use disaggregate household or individual level data to estimate the probability with which any household or individual will make trips. The outcome can then be aggregated to predict the number of trips produced.
Step 1. Choose File > Open Workspace and open the workspace CrossClassification.wrk. TransCAD displays a map of Vermont zones and a cross-classification table.
Step 2. Choose Planning > Trip Productions > Cross-Classification to display the Cross-Classification box.
Step 3. Choose MCD from the Input Data drop-down list.
Step 4. Choose All Zones from the Using drop-down list and Vmt_crcl from the Trip Rate Table list.
Step 5. Choose all three trip purposes that are shown in the Rate Fields scroll list.
Step 6. Click Choose Segments to display the Choose Zone/Subzone fields dialog box.
Step 7. Click Households in the Available Fields scroll list and click Add>>.
Step 8. Click OK to return to the Cross-Classification dialog box.
Step 9. Choose \[AUTO/HH\] from the drop-down list in the Avg Car/HH column and \[INC/HH\] from the drop-down list in the Avg Inc/HH column.
Step 10. Click OK to display the Output File Settings dialog box.
Step 11. Type “First Name-TG-CC” as the Output Table file name in the Short File Name column and click OK. TransCAD computes the productions for all zones and all purposes and displays a dataview of the cross-classification results in a joined view.
Step 12. Click Close to close the dialog box and scroll to the far right of the dataview to see the trip productions.
Step 13. Choose File > Close All to close the map and dataviews.
Step 1. Choose File > Open and open the binary file TG_ZNREG.BIN. This database contains the census data on each tract in Nassau County, New York.
Step 2. Choose Statistics > Model Estimation to display the Model Estimation dialog box.
Step 3. Click the Regression radio button.
Step 4. Choose \[Work Trips Per HH\] from the Dependent Var drop-down list.
Step 5. Click Independent Variables to display the Choose Independent Variables dialog box.
Step 6. Control click on \[People Per HH\], \[Age\<=5 Per HH\], \[25+ College Grad %\], and \[Veh Per HH\] in the Available Fields scroll list and click add.
Step 7. Click OK to return to the Model Estimation dialog box.
Step 8. Click Estimate to estimate the model.
Step 9. Click Save Model to display the Save Model As dialog box.
Step 10. Type “First Name-TG-R” as the file name and click Save.
Step 11. TransCAD produces a .mod file (called First Name-TG-R.mod) that contains the estimated parameters of the regression equation, including goodness-of-fit measures, estimates of the coefficients, and t-statistics.
Step 12. Click Close to close the Model Estimation dialog box.
Step 13. Choose Planning > Trip Productions > Apply a Model.
Step 14. Choose the model file First Name-TG-R.mod and click Open to display the Forecast dialog box.
Step 15. Choose TG_ZNREG from the Apply To drop-down list.
Step 16. Choose \[Forecasted WTrips\] from the Results in drop-down list.
Step 17. Click the Regression radio button.
Step 18. Click OK. TransCAD applies the model to each record, stores the forecasted variable in the field \[Forecasted WTrips\] of the table TG_ZNREG, and displays the Results Summary dialog box.
Step 19. Click Close.
Step 20. Scroll to the far right to see the results. Step 21. Choose File > Close to close the dataview.
Step 1. Choose File > Open and open the binary file Survey.bin. This database contains a subset of the fields from the PUMS person records for Delaware.
Step 2. Choose Statistics > Model Estimation to display the Model Estimation dialog box.
Step 3. Click the Binary Logit radio button.
Step 4. Choose \[Worked Last Week?\] from the Dependent Var drop-down list.
Step 5. Click Independent Variables to display the Independent Variables dialog box.
Step 6. Control click on \[Age over 16 ?\] , \[Age over 65 ?\] , \[Male ?\] , and \[Non-White\] in the Available Fields scroll list, and click Add.
Step 7. Click OK.
Step 8. Click Estimate to estimate the model.
Step 9. Click Save Model to display the Save Model As dialog box.
Step 10. Type “First Name-TG-LM” as the File Name and click Save.
Step 11. TransCAD produces a .mod file (called First Name-TG-LM.mod) that contains the estimated parameters of the regression equation, writes the results to the master report file, including goodness-of-fit measures, estimates of the coefficients, and t-statistics.
Step 10. Click Close to close the Model Estimation dialog box.
Step 12. Choose File > Close to close the dataview.
In many ways, estimating trip attractions is similar to estimating trip productions because the problem is the same: predicting the number of trips attracted by relating the number or frequency of trips to the characteristics of the individuals, the zone, and the transportation network. Thus, the three methods described above may also be used to estimate the number of trips attracted to a zone.
Trip distribution models are used to predict the destination choices of trip makers. Usually, in trip distribution a new flow matrix is forecasted based on estimates of future productions and attractions and estimates of the costs of travel between origins and destinations.
Trip distribution models can be applied at either an aggregate or a disaggregate level. Aggregate trip distribution models are typically used to predict flows between origin and destination zones. Three categories of aggregate trip distribution methods predominate in urban transportation planning:
Growth Factor Methods:
These involve scaling an existing matrix by applying multiplicative factors to matrix cells. These methods are usually encountered when there is no information available concerning the network interzonal distances, travel times, or generalized costs.
Gravity Models:
The typical inputs include one or more flow matrices, an impedance matrix reflecting the distance, time, or cost of travel between zones, and estimates of future levels productions and attractions. The gravity model explicitly relates flows between zones to interzonal impedance to travel.
Destination Choice Models:
These generally take the form of discrete choice models that evaluate utility functions for various potential destinations and ascribe probabilities to the same. The utilities can be a function of destination zone attributes as well as origin-destination skims.
Step 1. Choose File > Open Workspace and open the workspace DistributionApplyGrowthFactor.WRK. A map of Utown and an O-D matrix are displayed.
Step 2. Choose Planning > Trip Distribution > Growth Factor Method to display the Growth Factor Balancing dialog box.
Step 3. Choose UTOWN Base OD from the Matrix File drop-down list.
Step 4. Choose Production from the Constraint Type radio list.
Step 5. Check the box next to the HBW matrix.
Step 6. Click on the cell in the Production column and choose \[HBW_P 2000\] from the drop-down list.
Step 7. Click OK to display the Output File Settings dialog box.
Step 8. Type “First Name-TD-GF” as the file name in the Short File Name cell and click OK. TransCAD applies the growth factor model and displays the Results dialog box.
Step 9. Click Close. TransCAD displays the Results Summary dialog box.
Step 10. Click Close. TransCAD displays the Growth Factor Balanced (HBW) matrix.
Step 11. Choose File > Close All to close all of the windows.
Step 1. Choose File > Open Workspace and open the workspace DistributionApplyGravity.WRK. A map and a friction factor matrix are displayed.
Step 2. Choose Planning > Trip Distribution > Gravity Application to display the Gravity Application box.
Step 3. Choose TAZ from the Table drop-down list, FRICTION FACTORS from the FF Table drop-down list, TIME from the FF Time drop-down list, Doubly from the Constraint drop-down list, Shortest Path from the Impedance Matrix drop-down list, and None from the FF Matrix and K Matrix drop-down lists.
Step 4. Change the name of the Purpose 1 purpose by typing “HBW” in the cell in the Purpose row. HBW_P is automatically chosen in the Production row and HBW_A is automatically chosen in the Attraction row.
Step 5. Make the following changes to the HBW purpose: - Click on the cell in the Method row and choose Gamma from the drop-down list. - Type “20” in the Iteration row. This limits the procedure to a maximum of 20 iterations for this trip purpose. - Type 28507 for the value of a, 0.02 for the value of b, and 0.123 for the value of c. - Verify that Shortest Path - FF_Time is the chosen field in the Impedance Core row.
Step 6. Click “plus sign” to add a second purpose.
Step 7. Change the name of the new purpose to “HBNW.” HBNW_P is automatically chosen in the Production row and HBNW_A is automatically chosen in the Attraction row.
Step 8. Make the following changes to the HBNW purpose: - Click on the cell in the Method row and choose Inverse from the drop-down list. - Type 1.4 for the value of b. - Verify that Shortest Path - FF_Time is the chosen field in the Impedance Core row.
Step 9. Click “plus sign” to add a third purpose.
Step 10. Change the name of the new purpose to “NHB.” NHB_P is automatically chosen in the Production row and NHB_A is automatically chosen in the Attraction row.
Step 11. Make the following changes to the NHB purpose: - Click on the cell in the Method row and choose Table from the drop-down list. - Click on the cell in the F Factor row and choose NHB_FF from the drop-down list. - Verify that Shortest Path - FF_Time is the chosen field in the Impedance Core row.
Step 12. Click OK to display the Output File Settings dialog box.
Step 13. Type “First Name-TD-GM” as the file name in the Short File Name cell and click OK. TransCAD evaluates the three models, displays a Results dialog box stating that all three models converged.
Step 14. Click Close. TransCAD displays the Results Summary dialog box.
Step 15. Click Close. TransCAD displays a matrix view containing the results.
Step 16. Choose File > Close All to close all of the windows.
Mode choice models are used to analyze and predict the choices that individuals or groups of individuals make in selecting the transportation modes that are used for particular types of trips. Typically, the goal is to predict the aggregate share or absolute number of trips made by mode for each origin-destination pair. Mode choice models may also be applied on disaggregate lists of individuals and are often employed in Activity-Based Models. The modeling concepts underlying mode choice models may also be applied to predict other choices and shares such as household auto ownership splits, time of day choice, etc. The mode choice component of a travel demand model is estimated using individual-level data obtained from a survey, and forecasts are subsequently based upon aggregate, zonal segment level explanatory variables.
Discrete choice models are in many respects a substitute for regression models when the dependent variable is qualitative or categorical rather than continuous. Discrete choice models are formulated as stochastic models, in which the probability that a particular response is observed is a function of a set of explanatory variables. There are a variety of functional forms that can be proposed for the explanation of discrete choice. The Multinomial Logit (MNL) and Nested Logit (NL) models are used extensively.
Multinomial Logit (MNL) Model
MNL involves a decision-maker choosing exactly one alternative from a set of available discrete alternatives. For example, the figure below illustrated a mode choice situation in which individuals choose one of Drive Alone, Carpool or Bus to make certain type(s) of trips:
Step 1. Choose File > Open Workspace and open the workspace ModeChoiceEstimation.wrk.
Step 2. Choose Planning > Mode Split > Logit Model Estimation to open the Logit Model Estimation box.
Step 3. Click the Load button and select the model file MultinomialLogitModelEstimation.mdl.
Step 4. Click the Estimate tab and enter an output file name.
Step 5. Click Save and select a file name to save the model.
Step 6. Click Run. TransCAD estimates the MNL model, reports the results in a report form, and displays the Results Summary dialog box.
Step 7. Click Close. TransCAD opens the Load Confirmation dialog box. Click Yes.
Step 8. Click the Utilities tab. The Coefficient column now contains the new estimated parameters.
Step 9. Double-click on the nodes in the tree view window to see the estimated ASC values. Step 10. Choose File > Close All to close all the windows.
Step 1. Choose File > Open Workspace and open the workspace ModeChoiceAggregateApplication.wrk.
Step 2. Choose Planning > Mode Split > Logit Model Application to open the Logit Model Application box.
Step 3. Click the Load button and select the model file MultinomialLogitAggregateModel.mdl.
Step 4. Click the Apply tab and select additional outputs by checking “Output Utility Values” box.
Step 5. Check the “Open Outputs” box to ensure that the output files are opened after the model has been applied.
Step 6. Click Run.
Step 7. Click Yes in the Confirmation dialog box to save the changes, type “First Name-MC-MNL” as the file name and click Save. The Mode Choice Model Application Outputs dialog box is displayed with file names for each of the desired outputs.
Step 8. Check the Overwrite All Files box and click OK. TransCAD applies the Multinomial Logit model, reports the results in a report form, and displays the Results summary dialog box.
Step 9. Click Close. TransCAD opens the Utility, Probability and Applied Totals matrices. Step 10. Choose File > Close All to close all of the windows.
Nested Logit (NL) Model
When dealing with choice models that include several alternatives, there often exist natural groupings of alternatives and/or a natural hierarchy to the decision being made. A nested logit model is often represented using a tree structure, which visually represents groupings or hierarchies of the choice alternatives. For example, in mode choice, the tree may be:
In this case, the decision process can be thought of as occurring at the two levels. First, the traveler decides whether to take transit or auto. If transit is chosen, the traveler further decides whether to take the bus or light rail. Similarly, if auto is chosen, the traveler decides whether to drive alone or carpool. However, note that it is in fact a join decision, in that whether a traveler chooses transit or auto depend on the characteristics of the lower level alternatives. The nested logit model provides a mathematical representation of this joint decision.
Step 1. Choose File > Open Workspace and open the workspace ModeChoiceEstimation.wrk.
Step 2. Choose Planning > Mode Split > Logit Model Estimation to open the Logit Model Estimation box.
Step 3. Click the Load button and select the model file NestedLogitModelEstimation.mdl.
Step 4. Click the Estimate tab and enter an output file name.
Step 5. Click Save and select a file name to save the model.
Step 6. Click Run. TransCAD estimates the Nested Logit Model, reports the results in a report form and displays and the Results Summary dialog box.
Step 7. Click Close. TransCAD opens the Load Confirmation window. Click Yes.
Step 8. Click the Utilities tab. The Coefficient column row contains the new estimated parameters.
Step 9. Double-click on the nodes in the tree view window to see estimated values of the ASCs and Thetas.
Step 10. Choose File > Close All to close all of the windows.
Step 1. Choose File > Open Workspace and open the workspace ModeChoiceAggregateApplication.wrk.
Step 2. Choose Planning > Mode Split > Logit Model Application to open the Logit Model Application box.
Step 3. Click the Load button and select the model file NestedLogitAggregateModel.mdl.
Step 4. Click the Apply tab and select additional outputs by checking the “Output Logsum Values” and “Output Utility Values” boxes.
Step 5. Check the “Open Outputs” box to ensure that the output files are opened after the model has been applied.
Step 6. Click Run.
Step 7. Click Yes in the Confirmation dialog box to save the changes, type “First Name-MC-NL” as the file name and click Save. The Mode Choice Model Application Outputs dialog box is displayed with file names for each of the desired outputs.
Step 8. Check the “Overwrite all files” box and click OK. TransCAD applies the Nested Logit model, reports the results in a report form and displays the Results Summary dialog box.
Step 9. Click Close. TransCAD opens the Utility, Logsum, Probability and Applied Totals matrices.
Step 10. Choose File > Close All to close all of the windows.
Traffic assignment models are used to estimate the traffic flows on a network. These models take as input a matrix of flows that indicate the volume of traffic between origin and destination (O-D) pairs. They also take input on the network topology, link characteristics, and link performance functions. The flows for each O-D pair are loaded onto the network based on the travel time or impedance of the alternative paths that could carry this traffic. TransCAD provides the widest array of traffic assignment procedures that can be used for modeling urban traffic. These procedures include numerous variants that can be used for modeling intercity passenger and freight traffic.
Traffic assignment is a key element in the urban travel demand forecasting process. The traffic assignment model predicts the network flows that are associated with future planning scenarios and generates estimates of the link travel times and related attributes that are the basis for benefits estimation and air quality impacts. The traffic assignment model is also used to generate the estimates of network performance that are used in the mode choice and trip distribution or destination choice stages of many models.
Assignment UE assignment is the recommended method for traffic assignment unless a more advanced model is employed. UE procedures use an iterative process to achieve a convergent solution, in which no travelers can improve their travel times by shifting routes. In each iteration, TransCAD computes network link flows that are based upon flow-dependent travel times. The formulation of the UE problem is a mathematical program and the Frank-Wolfe (FW) solution method is one of several employed in TransCAD. Another way to compute a UE assignment is to use an alternative algorithm such as path-based algorithm.
Assignment SO computes an assignment that minimizes total travel time on the network. Under SO assignment, no users can change routes without increasing the total travel time on the system, although it is possible that travelers could reduce their own travel times. SO assignment can be thought of as a model in which total system cost is minimized when travelers are told which routes to use. Obviously not a behaviorally realistic model, SO assignment can be useful in analyzing Intelligent Transportation System (ITS) scenarios.
Step 1. Choose File > Open Workspace, then open the workspace TrafficAssign.wrk. TransCAD displays a street map and a flow matrix. You want to assign flow to the links using the User Equilibrium model.
Step 2. Choose Planning > Static Traffic Assignment > Traffic Assignment to display the Traffic Assignment dialog box.
Step 3. Choose N-Conjugate UE from the Method drop-down list, AM Peak Period Trips from the Matrix File drop-down list, Total (7-9) from the Matrix drop-down list, and type “10” in the Iterations edit box.
Step 4. In the Field column of the grid view, verify that \[Freeflow Time\] is chosen for Time and \[AB_AMCapacity/BA_AMCapacity\] is chosen for Capacity drop-down list. The other settings are correct.
Step 5. Click Options to display the Options dialog box. \
Step 6. Check the Create Theme box, type “3” in the Max V/C edit box and click OK.
Step 7. Click OK to display the Output File Settings dialog box.
Step 8. Type “First Name-TA-UE” as the Flow Table file name in the Short File Name cell and click OK. TransCAD assigns the flow to the links in the network and displays the Results Summary dialog box.
Step 9. Click Close. TransCAD displays the results in a joined view and displays a color theme of the volume-to-capacity ratio and a scaled-symbol theme of flow on the map.
Step 10. Choose File > Close All and click No to close the map, dataview, and matrix without saving changes.
Step 1. Choose File > Open Workspace, then open the workspace TrafficAssignCriticalLink.wrk. TransCAD displays a map and a flow matrix. You want to assign flow to the links using the User Equilibrium model and report the O-D traffic over the Critical Links.
Step 2. Choose Planning > Static Traffic Assignment > Traffic Assignment to display the Traffic Assignment dialog box.
Step 3. Choose N-Conjugate UE from the Method drop-down list, AM Peak Period Trips from the Matrix File drop-down list, and Total (7-9) from the Matrix drop-down list.
Step 4. In the Field column of the grid, verify that \[Freeflow Time\] is chosen for Time row and \[AB_AMCapacity/BA_AMCapacity\] is chosen in the Capacity row.
Step 5. Type “10” in the Iterations edit box. The other settings are correct.
Step 6. Click Options to display the Options dialog box and click the Other Options tab.
Step 7. Check the Select Link/Zone Queries box to open the File Open dialog box. Choose the CriticalLink.qry query file and click Open. The queries appear in the scroll list.
Step 8. Highlight the I-495 Westbound query and click OK to return to the Traffic Assignment dialog box.
Step 9. Click OK to display the Output File Settings dialog box.
Step 10. Highlight and change the Flow Table file name to “First Name-TA-CF.”
Step 11. Highlight and change the Critical Matrix file name to “First Name-TA-CM.”
Step 12. Click OK. TransCAD assigns the flow to the links in the network and displays the Results Summary dialog box.
Step 13. Click Close. TransCAD displays the results in a joined view and displays the Critical Link Analysis matrix, indicating the O-D pairs and flows that utilize the critical link. The results are displayed in each direction of the link.
Step 14. Choose Map > Thematic Mapping > Size to display the Scaled Symbol Theme dialog box.
Step 15. Choose \[AB_Flow_I-495 Westbound\] near the button of the scroll list and click OK. TransCAD adds a scaled-symbol theme to the map showing flow patterns for everyone who travels over the critical links.
Step 16. Choose File > Close All and click No to close all of the windows without saving.
MMA is a flexible master assignment routine designed for use in major metropolitan areas and is directly applicable in statewide or interregional models. The MMA model is a generalized cost assignment that lets you assign trips by individual modes or user classes to the network simultaneously. This method allows you to explicitly model the influence of toll facilities of all types, as well as HOV and HOT facilities. Each mode or class can have different network exclusions, congestion impacts (passenger car equivalent values), values of time, and toll costs.
Step 1. Choose File > Open Workspace, then open the workspace TrafficAssignMultiModal.wrk. TransCAD displays a map of highways in Massachusetts, along with a flow matrix for cars, light trucks and heavy trucks, and a toll matrix describing tolls between entry and exit nodes on the Massachusetts Turnpike. A network is also loaded. You want to assign the multiple-mode flow matrix to the network using fixed tolls and the toll matrix.
Step 2. Choose Highways from the drop-down list on the Standard toolbar.
Step 3. Choose Planning > Static Traffic Assignment > Multi-Modal Multi-Class Assignment to display the Multi-Modal Multi-Class Assignment dialog box.
Step 4. Verify that N Conjugate UE is chosen from the Method drop-down list, Bureau of Public Roads (BPR) is chosen from the Delay Function drop-down list and AM Trips (7:00-9:00) is chosen from the O-D Matrix drop-down list.
Step 5. Click Tolls to display the Toll Settings dialog box, choose Mass Pike Toll Schedule from the Toll Matrix drop-down list and click OK to return to return to the Multi-Modal Multi-Class Assignment box.
Step 6. Click on the Choose OD Classes button, highlight all available matrices and click on the Add >> button to select all matrices and click OK.
Step 7. Make the following changes in the Cars – Class 1 row: - Click on the cell in the Link Toll column and choose \[Car Toll\] from the drop-down list - Click on the cell in the OD Toll column and choose Cars – Class 1 from the drop-down list
Step 8. Make the following changes in the Truck – 4T row: - Click on the cell in the Link Toll column and choose \[Truck 4T Toll\] from the drop-down list - Click on the cell in the OD Toll column and choose Truck – 4T from the drop-down list
Step 9. Make the following changes in the Trucks – SU row: - Click on the cell in the PCE Global column and type “2.0” - Click on the cell in the Link Toll column and choose \[Truck SU Toll\] from the drop-down list - Click on the cell in the OD Toll column and choose Trucks – SU from the drop-down list
Step 10. Make the following changes in the Trucks – Combo row: - Click on the cell in the PCE Global column and type “3.0” - Click on the cell in the Link Toll column and choose \[Truck Combo Toll\] from the drop-down list - Click on the cell in the OD Toll column and choose Trucks – Combo from the drop-down list - Click on the cell in the Exclusion Set column and choose Truck Combo Exclusion from the drop-down list
Step 11. In the Delay Function Parameters grid, verify that \[AB_FFTime/BA_FFTime\] is the field chosen for Time and \[AB_AMCapacity/BA_AMCapacity\] is the field chosen for Capacity. The other settings are correct.
Step 12. Click OK to display the Output File Settings dialog box.
Step 13. Type “First Name-TA-MMA” in the File Prefix edit box and click OK. TransCAD assigns the flows to the links in the network and displays the Results Summary dialog box.
Step 14. Click Close. TransCAD displays the results in a joined view.
Step 15. Choose Map > Thematic Mapping > Size to display the Scaled Symbol Theme dialog box.
Step 16. Choose AB_Flow_Truck – Combo from the scroll list and click OK. TransCAD adds a scaled-symbol theme of the assigned flows on the map.
Step 17. Choose File > Close All and click No to All to close all of the windows without saving.
Vehicle Routing Many businesses and government agencies transport goods from one or more central locations to a set of destinations. It is important to manage these operations efficiently, both to reduce operating costs and to ensure that pickups and deliveries adhere to reasonable service standards. This general problem is known as the vehicle routing problem. Solving the vehicle routing problem involves determining how many vehicles are required to service the destinations and developing a route and schedule for each one. Because there are many variations of the problem, it can be very difficult to solve. TransCAD provides a rich set of vehicle routing tools that solve various types of routing problems.
Step 1. Choose File > Open, then open the map VehicleRoutingwithTimeWindows.map. TransCAD displays a map with two depots and 25 stops.
Step 2. Choose File > Open and open the network BOSTON.NET.
Step 3. Choose Routing/Logistics > Vehicle Routing to display the Vehicle Routing Wizard.
Step 4. Click the Create New Vehicle Routes radio button, verify that Delivery is chosen from the Operations Mode drop-down list and click Next to display the Customers page.
Step 5. Notice that TransCAD already has chosen to use all features in the Clients layer and has found the fields for name, demand, service time, and time window. Click Next to display the Depots page.
Step 6. Notice that TransCAD already has chosen to use all features in the Depots layer and has found the fields for name, open time, and close time. Click Next to display the Vehicles page.
Step 7. Click “green plus sign” six times to add 6 vehicles.
Step 8. Click and drag to highlight all of the cells in the Cost column and type 100 to set the costs for all six vehicles.
Step 9. Click and drag to highlight all of the cells in the Capacity column and type 50 to set the capacities for all six vehicles.
Step 10. For vehicles 4-6, choose Free Port Depot from the drop-down list in the Depot column.
Step 11. Click Next to display the Options page.
Step 12. Enter 8 in the Maximum Route Duration box, choose Time (in hours) from the Balance Routes by drop-down list, and click Finish. TransCAD displays the Save Vehicle Routing Results In dialog box.
Step 13. Right-click in the dialog box, choose New > Folder, name the folder “First Name-VRP-Results,” and click Select Folder.
Step 14. Click OK in the status dialog box. TransCAD adds the routes to the map and opens the Vehicle Routing Manager. Notice the five routes have approximately even durations.
Step 15. Click “plus sign” next to a route to see the stops that route services.
Step 16. Right-click the itinerary description at the top of the list and choose Create Report. TransCAD creates a PDF report. Scroll through the PDF to see the itinerary for each route. Close the report when you are done.
TransCAD includes a set of procedures for solving network flow problems. These problems involve efficient delivery of goods or services and arise both in transportation and in many other contexts. For example: - You need to ship an inventory of goods from 15 warehouses to 100 retail centers, each with a given demand, and you want to determine which warehouses should service which retail centers to minimize the total transportation cost. - You need to route empty rail cars from their current locations to locations where they are required for new loads, taking into account rail traffic density by link.
Step 1. Choose File > Open Workspace, then open the workspace TransportationProblem.wrk. TransCAD displays a map of Washington State. On the map, there are three warehouses and 20 customers. You want to determine which warehouse ships tSo which customer. Also opened is a travel time matrix between each warehouse and each customer.
Step 2. Choose Routing/Logistics > The Transportation Problem to display The Transportation Problem dialog box.
Step 3. Choose WAREHOUSE from the Layer drop-down list under Origin Settings and choose CUSTOMER from the Layer drop-down list under Destination Settings. Step 4. Verify that Wa_hwy.net is the active network.
Step 5. Choose TIME from the Cost Field drop-down list.
Step 6. The other settings are correct. Click OK to display the Output File Settings dialog box.
Step 7. Change the output file names as done above and click OK. TransCAD solves the Transportation Problem and assigns the shipments to links in the network. A joined view is opened showing the flow on each link.
Step 8. Click on the map window or choose Window > U.S. Highways to make the map the active window. TransCAD shows a scaled-symbol theme showing the flow on each link.
Step 9. Choose File > Close All and click No to close the map and matrix without saving any changes.
Facility Location Models are used to identify good locations for warehouses, hospitals, retail stores, manufacturing facilities, and other types of facilities. In general, the goal in locating such facilities is either to provide a high level of service, to minimize operating costs, or to maximize profits. TransCAD solves many different types of facility location problems, with applications in both the public and private sectors. Here are two examples: - You need to determine the best location for a new branch of a public library. Your goal is to provide the best overall level of access to city residents. - You need to determine the best location for a new police station. Your goal is to reduce the maximum distance a patrol car needs to travel from the station to a resident’s home.
Step 1. Choose File > Open Workspace, then open the workspace FacilityLocation.wrk. TransCAD displays a map of the Northeast Sales Region. On the map, there are 46 customers, one existing facility and 8 candidate facilities. A matrix file is also opened. You want to determine what two facilities to add to minimize shipping cost.
Step 2. Choose Routing/Logistics > Facility Location to display the Facility Location dialog box.
Step 3. Type “2” in the # New Facilities edit box. Step 4. Choose Facility from the Layer drop-down list under Facility Settings.
Step 5. Choose Customer from the Layer drop-down list under Client Settings.
Step 6. Choose Demand from the Weight drop-down list.
Step 7. Click OK to display the Output File Settings dialog box.
Step 8. Type “First Name-FL” in the Short File Name cell and click OK. TransCAD determines the two new facilities to open that, in conjunction with the existing facility in New York, will minimize the cost of shipping to the 46 customers. A selection set named New Facilities, containing these facilities, is displayed on the map. A table is joined to the Customer layer showing which facility will service each customer. The results summary is also displayed. Click Close to close the Results Summary dialog box.
Step 9. Click on the map or choose Window > Map1 to make the map the active window and see the new facilities to open. Step 10. Choose File > Close All and click No to close the map, matrix and joined view without saving nay changes.