The purpose of the vehicle path analysis dialog box is to assist the user in understanding the multi-dimensional mapping and sequential linkage from OD pairs, to the corresponding paths, vehicles and links. At the termination of the DTA algorithm, for each OD pair and departure time combination, there exist multiple paths assigned to vehicles, depending on different user information classes (e.g. historical information or pre-trip information) and vehicle occupation types (LOV/HOV). Different vehicles between the same OD pair departing at different departure time would have different experienced travel times. Along a vehicle path, the travel speed and delay on different links also significantly vary depending on dynamic traffic conditions. The dialog box provides a rich amount of information that can be used by a user for various analysis purposes. A few example uses of this dialog box include:
Step 1: Critical OD pairs The user can view critical origin-destination pairs by defining the following criteria.
In the above screen shot, the user wants to find critical OD pairs heading to destination zone 12 with at least 1 vehicle and travel time >= 5 min. In the OD pair list, the user selects OD pair 3→12, which carries 86 vehicles, and the average travel time for those vehicles is 10.11 min.
Step 2: The user can define “user attributes filter” to further select vehicles along the previously selected OD pair (e.g. 3→12 in the screen shot). The selection criteria include
Step 3: Path list
The selected vehicles (as a result of filtering from steps 1 and 2) are further classified by different paths. In the screen shot, there are 2 paths, while the first path carries 46 vehicles with the corresponding the average travel time of 10.11 min.
Step 4: Vehicle list
The user can select a path from the path list to view the vehicles along this path. If the user selects the option “all” in the path list, then the selected vehicles on all the paths (as a result of filtering from steps 1 and 2) are entirely displayed in the vehicle list.
In the vehicle list, the vehicle ID, departure time, travel time and experienced toll (if applicable) are displayed individually for each vehicle.
As there might be a large number of vehicles in the vehicle list, the user can directly input a vehicle id to find a vehicle. The selected vehicle is highlighted in pink on the network view, as shown in the figure below.
Note: the user can input and find a vehicle id which is not previously listed in the vehicle list.
Step 5: Link list For a selected vehicle, the sequence of its traversing link sequence is displayed in the link list. For each link, the corresponding upstream node (from_node), downstream node (to_node), link length, and the vehicle arrival time (at the upstream node), traveling speed and stop time are display.
The user can further select a link from the link list, and the selected link is highlighted in a solid pink line on the network view.
Important Notes: The number of vehicles counted in Vehicle Path Analysis by definition has to be less than the actual OD trips because this tool captures only those vehicles that have arrived at the destination by the simulation end. In other words, at simulation end, there may still be vehicles in the network. Their trips have not finished; therefore, their actual travel time are not included in the calculation.
The Impacted Vehicle Analysis is an extension of the Vehicle Path Analysis in providing the capability to examine the dynamic mapping and linkage of OD pairs from a multi-filtered vehicle analysis and associated utilized paths. However, this tool allows the user to extensively compare vehicle diversions for incident management scenarios from the UE or Base Case scenario. In other words, the Impacted Vehicle Analysis provides a platform to compare an Alternative Case of various ITS management strategies (see MUC Traveler Information) or in-place incidents against a UE or Base Case. The important factor for proper comparison is the use of vehicle and path information from the UE Case. DynusT has the ability to model this information.
Like the Vehicle Path Analysis, the Impacted Vehicle Analysis dialog box provides a rich amount of information that can be used by the user for various analysis purposes, but now with a point of reference for comparison. The dialog box provides information including:
The steps for performing the analysis with this tool are as follows:
PLEASE NOTE: The number of vehicles counted in Impacted Vehicle Analysis by definition has to be less than the actual OD trips because this tool capture only those vehicles that have arrived at the destination by the simulation end. In other words, at simulation end, there may still be vehicles in the network. Their trips have not finished; therefore, their actual travel time are not included in the calculation.
The output files from DynusT are in *.dat format and can be opened in any text editor. These files are available for Post-Processing use for advanced user needs.
The following is a list of *.dat text files created from the DynusT simulation/assignment procedures.
Error Log (Errorlog.dat)
The error log lists the error messages that cause the program to terminate. It indicates what the error is and what caused it.
The warning file gives a list of messages specifying causes in the model that may have unwanted results. These causes are mostly due to poor network modeling. The messages are to identify these problems in the model to the user. The warning messages will not cause DynusT to terminate.
Summary Statistics (summarystat.dat)
The summary statistics gives all information used and all information generated during the run of the simulation. Some of these summaries include:
Summarystat.dat (Summary Statistics output file) lists the statistics for the vehicles still in the network and those that are outside the network together. The following figure shows an example of the summarystat.dat.
The density file lists the densities (pc/mile/lane) that occur on each link during the simulation intervals, and the average of the density over the number of intervals. The figure below shows an example of the density file. The top text lines show an averaging period and reporting period of 10 intervals (or one minute).
The speed file lists the speeds (miles/hr) occuring on the links during each simulation interval, and averaged over the number of intervals. The number of the intervals is specified in the output_option.dat file. An example of what this file looks like is given below. The top text lines show averaging periods and reporting periods of 10 simulation intervals (or one minute). The first line gives the time interval in minutes. The next line give the link information. The example below has an average of 40 mph on link 1 (the first position on the horizontal line), link 2 has an average speed of 40 mph, and link 3 has an average speed of 15 mph. The positions continue until all links have been accounted for. The process then repeats for each of the averaging time intervals.
The queue files show the amount of vehicles in each queue on the links during the simulation interval. This is averaged over the number of intervals given. The reporting period is the average of the interval. An example of the queue file is shown below. The first line gives the time interval in minutes. On the next line is the link information. Below, the file shows that 0 vehicles are queued on link 1, 0 on link 2, and 0 on link 3. The process is repeated for each of the averaging time intervals.
Accumulated Volume (OutAccuVol.dat)
The accumulated volume file counts the cumulative amount of vehicles that go through the mid-point of the link, at each minute. An example of this file is shown below. The accumulated volume file is always created.
The top line gives the reporting period of 10 simulation intervals in the file below. The first line of data gives the time interval in minutes. The next line gives link information. Below, the link information is given at min 10.0, 2 vehicles pass through link 1, 1 vehicle passes through link 2, and 0 vehicles pass through link 3. The process is repeated for each time interval.
The network statistics file gives the statistics of the network. This includes:
Below is an example of what the network statistics file looks like.
Vehicle Path Information (AltPath.dat)
Vehicle path information is very important for post-processing. Its format is shown below. The first number is an internal path ID, the second number on each line is the vehicle ID, the third number is the vehicle type, the fourth number is the origin zone, the fifth number is the destination zone, the sixth number is the number of nodes in the path, and the following numbers are numbered nodes on the path the vehicle takes. The last node is an internal centroid node that is not within the visible network framework, but is the method with which the vehicle leaves the network.
In the example below the vehicle ID number is 45. The vehicle type is 1, the origin zone is 10, the destination node is 7, there are three nodes in the path. The vehicle passes through node 93, node 141, and then leaves the network out the internal centroid node 900007.
Vehicle Time Information (AltTime.dat)
The following figure is an example of the AltTime.dat file. Each number is a time stamp associated with each node in the vehicles path.
Vehicle Trajectory (vehtrajectory.dat)
The vehicle trajectory file gives traffic information and the itinerary that goes with each vehicle. Information is given first about the vehicles that have exited the network, and the the information about those still in the network at the end of the simulation run time. An example of the vehicle trajectory file is given below.
Those vehicles that remain in the network at the end of the simulation have the same output as the vehicles that have exited. The only difference is the the statistics that refer to these vehicles still in the network are reported at the downstream node of its traveled link.
|Veh #||The Vehicle Number|
|Tag|| Type of tagging. Tagged vehicles are vehicles that have recorded characteristics.
Those tagged vehicles are used in calculating the average characteristics of vehicles in the network:
0: not tagged
1: tagged vehicle that did not reach its destination before the end of simulation
2: tagged vehicle that reached its destination
|Class||User Class 1: non-responsive; 2: SO; 3: UE; 4: enroute info; 5: VMS-responsive|
|Total Travel Time||Total Time in the System|
|# of Nodes||Number of Nodes the Vehicle Passes Through|
|VehType||Vehicle Type 1: Passenger car 2: Truck 3: HOV|
|LOO||Level of occupancy 1: LOV; 2: HOV|
Vehicles that have already exited the system are listed first. Then under where it states “Vehicles Still in the Network” are listed the vehicles still in the network. The numbers on the second row refer to the list of the nodes the vehicle travels through, and the numbers on the third row is the time stamp of the vehicle in the system. Notice the start time and the first number on the third row may not match. The start time is the current time in the simulation that the vehicle starts. The number on the third row sets the time the vehicle entered the system as zero, and then determines the time the vehicle is at each node. Note: the number in the last column of this row will match the total travel time. The fourth row gives the time in which the vehicle was between nodes. Note: if this row is added, the sum will equal the total travel time. The fifth row gives the delay time at each node.
Output Vehicle Data (output_vehicle.dat)
The output vehicle data file specifies vehicle characteristics and travel plans. The table below has a more detailed description of the output vehicle data files and a figure giving an example of what the output vehicle data file looks like.
Description of the vehicle.dat input file
|Upper Left Hand Corner||Number of Vehicles to be loaded|
|# of vehicles in the file, Max # of stops||Maximum Number of Destinations for all Vehicles|
|usec||Upstream node of the generation link|
|dsec||Downstream node of the generation link|
|stime||Starting time of 1st vehicle (minutes)|
|vehcls||User class 1: unresponsive, 2: SO, 3: UE, 4: Enroute info, 5: VMS|
|vehtype||Type of 1st vehicle 1: cars, 2: trucks, 3: HOV|
|ioc||Occupancy level of 1st vehicle 1: LOV, 2: HOV|
|#ONode||Number of nodes in the path of 1st vehicle (enter 1 if path.dat will not be used)|
|#IntDe||Number of destinations along the path of the 1st vehicle including intermediate stops and final destination|
|info||En-route information indicator for 1st vehicle: 0: no info is available, 1: En-route info available|
|ribf||Indifference band (minutes) for switching 1st vehicle|
|comp||Compliance rate (0 – 1.0) (Class 4 users only, specify 0 for all other class users)|
|izone||Origin zone for 1st vehicle|
|Second Line, First Number||Zone number of the destination|
|Second Line, Second Number||The activity duration (min) at the destination. The activity duration for the final destination should always be zero.|
The first number in the figure above shows that there are 70247 vehicles to be loaded. The second number show that the maximum number of destinations in a vehicle path is 1. The third line shows that vehicle 1 is generated on a link with upstream node number 580 and downstream node number 583. Time for this vehicle begins at 0.0 min. The vehicle belongs to user class 3, of vehicle type 1, and is occupancy type 1.
The number of nodes in the path is 80. This vehicle has 1 destination, and does not have access to en-route information (Flag = 0) (no-info); so zeros need to be given for the indifference band and the compliance rate. The origin zone for this vehicle is 1.
The next record indicates that the previously specified destination is located in zone 135. There is only one destination so this destination (final destination) is located in zone 135 and has a 0 duration because it is already in the final destination.
Output Path (output_path.dat)
The output path file specifies the itinerary of the vehicles in the vehicle.dat file. The nodes in the vehicles path start with the upstream node of the generation links. The number of nodes listed for the vehicle matches the number of nodes specified in the vehicle.dat file. If the user only wants to use the vehicle.dat file the path.dat file must still be in the working directory, even if the file is empty. An example of what the output path file looks like is also given below.
The first number in the figure on the first line is the first vehicle with an upstream node number 580, the second node on the path is node 583, the third node in the path is node 578, the fourth node in the path is node 1044, the fifth node in the path is node 1045, and so on until the final destination node ( x - the last number on the line). This format is then repeated for all remaining vehicle-paths.
Output MUC Statistics (outmuc.dat)
The Output MUC statistics files gives the summary of the MUC assignment procedures. This file is always created even when only one simulation is ran, and maintains each iteration's simulation results. The file provides MUC MOE statistics for:
Output Options (output_option.dat)
The output options file allows the user to check which output files will be created in the simulation run and specify the time intervals. The following table gives the output files that can be chosen from.
|Out_LinkGen.dat (number of generated vehicles)||Number of simulation intervals over which number of vehicles on links will be averaged|
|OutLinkVeh.dat (number of vehicles)||Number of simulation intervals over which number of vehicles on links will be averaged|
|OutLinkQue.dat (vehicle queue length)||Number of simulation intervals over which vehicle queue on links will be averaged|
|OutLinkSpeedAll.dat (link speed)||Number of simulation intervals over which link speed will be averaged|
|OutLinkDent.dat (link density)||Number of simulation intervals over which link density will be averaged|
|OutLinkSpeedFree.dat (speed of moving vehicles)||Number of simulation intervals over which speed of moving vehicles will be averaged|
|OutLinkDentFree.dat (density of moving vehicles)||Number of simulation intervals over which density of moving vehicles will be averaged|
|OutLeftFlow.dat (number of left-turning vehicles)||Number of simulation intervals over which number of left-turning vehicles will be averaged|
|OutGreen.dat (green time at intersections)||Number of simulation intervals over which green time at intersections will be averaged|
|OutFlow.dat (number of vehicles crossing intersections)||Number of simulation intervals over which number of vehicles crossing intersections will be averaged|
The above text files are found under the text files drop down menu → open project files.
OutLinkGen.dat (number of generated vehicles)
OutLinkGen.dat gives the number of vehicles that are generated on each link during the simulation interval. The following figure is an example of what this output file looks like. The top text lines indicate an averaging and reporting period of 10 simulation intervals. The first record indicates the time interval in minutes (minute 1 in this example). The next line provides link information. In this example, it shows that zero vehicles were generated on link 1 (the first number), 1 vehicle was generated on link 2 (second number) and 3 on link 3(third number) over the 10 simulation intervals. The process is repeated for all averaging time intervals.
OutLinkVeh.dat (number of vehicles)
OutLinkVeh.dat gives the number of vehicles present on the links during the simulation interval, averaged over the number of simulation intervals. Below is an example of what this output file looks like. The top text lines indicate an averaging and reporting period of 10 simulation intervals. The first number indicates the time interval in minutes. The next line gives the link information.
OutLinkQue.dat (vehicle queue length)
OutLinkQue.dat gives the number of vehicles on each link during the simulation interval averaged over the number of simulation intervals. Below is an example of the output file. The first number indicates the time interval in minutes. The next line provides link information.
OutLinkSpeedAll.dat (link speed)
OutLinkSpeedAll.dat gives the speed (miles/hr) prevailing on each link per simulation interval, averaged over the number of simulation intervals. Below is an example of what this output file looks like. The top text line indicates an averaging and reporting period of 10 simulation intervals. The first line indicates the time interval in minutes. The next line gives link information. For example, this output file shows that link 1 has an average speed of 40.000 mph, link 2 has an average speed of 40.000 mph, link 3 has an average speed of 15.000 mph.
OutLinkDent.dat (link density)
OutLinkDent.dat gives the density (pc/mile/lane) on each link over the simulation interval, averaged over the number of simulation intervals. Below is an example of what this output file looks like. The top text line indicates an averaging and reporting period of 10 simulation intervals. The first number indicates the time interval in minutes. The next line gives link information. In this example, it shows that link 1 has an average density of 0.86 pc/mile/lane (first number) and link 2 has an average density of 0.28 pc/mile/lane (second number).
OutLinkSpeedFree.dat (speed of moving vehicles)
The OutLinkSpeedFree.dat output file gives the average speed (mph) for the moving vehicles (not in a queue) on each link per simulation interval, averaged over the number of simulation intervals. Below is an example of what this output file looks like. The top text line indicates an averaging and reporting period of 10 simulation intervals. The first number indicates the time interval in minutes. The next line gives link information. This example shows that moving vehicles on link 1 have an average speed of 40.000 mph (first number), moving vehicles on link 2 have an average speed of 40.000 mph (second number), moving vehicles on link 3 have an average speed of 15.000 mph (third number). This file is the same as OutLinkSpeedAll.dat, except it does not include stopped vehicles.
OutLinkDentFree.dat (density of moving vehicles)
OutLinkDentFree.dat gives the density (pc/mile/lane) on each link over the simulation interval, averaged over the number of simulation intervals. Below is an example of what this output file looks like. The top text line indicates an averaging and reporting period of 10 simulation intervals. The first number indicates the time interval in minutes. The next line gives link information. In this example, it shows that link 1 has an average density of 0.86 pc/mile/lane (first number) and link 2 has an average density of 0.28 pc/mile/lane (second number). This file is the same as to OutLinkDen.dat, except it does not include stopped vehicles.
OutLeftFlow.dat (number of left-turning vehicles)
The OutLeftFlow.dat output file gives the number of left-turning vehicles on the link per simulation interval, averaged over the number of simulation intervals specified. Below is an example of what this output file looks like. The top text line indicates an averaging and reporting period of 10 simulation intervals. The first number indicates the time interval in minutes. The next line gives link information. In this example, it shows that link 1 through link 5 have an average of 0.000 turning vehicles and link 6 has an average of 0.10 turning vehicles (sixth number).
OutGreen.dat (green time at intersections)
The OutGreen.dat output file gives the green time (seconds) for each approach per simulation interval, averaged over the number of simulation intervals. Below is an example of what this file looks like. The top text line indicates an averaging and reporting period of 10 simulation intervals. The first number indicates the time interval in minutes. The next line gives link information.
OutFlow.dat (number of vehicles crossing intersections)
The OutFlow.dat output file gives the number of vehicles that pass through the link per simulation interval, averaged over the number of simulation intervals. The file includes through, left-turning, and right-turning vehicles. Below is an example of what this output file looks like. The top text line indicates an averaging and reporting period of 10 simulation intervals. The first number indicates the time interval in minutes. The next line gives link information. In this example, it shows that an average of 0.200 vehicles (first number) pass through link 1, an average of 0.100 vehicles (second number) pass through link 2, and an average of 0.100 vehicles (third) pass through link 3.
Tollrevenue.dat contains the toll revenue collected for each toll link and for the entire toll facility at each iteration. For each performance measure, two columns are shown with the first one for auto and 2nd for trucks.
The convergence criteria for traffic assignment is commonly referred to as the Relative Gap (RG). This RG is a measure of how close the current assignment solution is to the optimal network assignment, better known as User Equilibrium (UE) which is the route choice model by which most traffic assignment methods use. This is based off of what is commonly known as Wardrop's First Principle, and is defined for static assignment cases as:
“For each O-D pair, at user equilibrium, the travel time on all used paths is equal, and (also) less than or equal to the travel time that would be experienced by a single vehicle on any unused path.”
Under the dynamic traffic assignment (DTA) case, the definition is enhanced to consider the time-varying conditions (see Dynamic Traffic Assignment). Because of the time dimension presented in the DTA solution algorithm and the simulation-based modeling scheme incorporating network heuristics based on the relationship between the mapping properties of link input flows and link/path travel times, attaining a unique solution is not feasible. However, the attainment of a stable solution can be reached under UE conditions acting as a guide to an approximate solution. The RG gives a measurement between the experienced travel time of the previous iteration and the next best path's travel time solved in the current iteration, for every OD pair at each departure time interval. So in essence, the RG is the change between the current iteration and the previous iteration.
So at each iteration l, paths k∈K within each origin o, destination d, departure time τ combination, the sum of differences between the total travel time Tn for all vehicles n and the shortest path travel time T* of the o,d,τ combination is divided by the sum of vehicles n along T*, thereby giving the normalized convergence criterion to a stable solution:
DynusT optimizes the best path based on the information from the simulation through an iterative procedure and changes the path.dat file with the next best path. The optimal result for the relative gap is 0, when the current iteration is no different than the previous iteration. This means the paths did not change because the paths are optimal. A 0 relative gap is difficult to obtain and requires many iterations. In most cases the user may specify a relative gap, 0.002 for instance. The user would run a number of iterations to determine when the program reaches that relative gap, perhaps 50 iterations, and then may use the number of iterations given in convergence.dat for the relative gap of 0.002 for any scenarios of that dataset.
The RG results from a DynusT run can be viewed from the output file titled Convergence.dat. The first column listed is the number of the iteration. The subsequent columns report the RG for each assignment time interval (typically 5 minutes) for each iteration. As the assignment/simulation procedure progresses, the RG values may fluctuate, but the overall development of values should continue to decrease down the list of iterations. This output file reports every assignment time interval for the length of the planning horizon; however, the calculation of the RG is accomplished for only the length of demand being generated. Therefore, the after the demand generation period is finished, the file will report a series of zeros for the remaining length of time in the planning horizon.
The time-varying link statistics utility allows the user to specify multiple links and output time intervals for which the flow rate (pc/ph) and average speed (mph) are to be generated for reporting or further analysis purposes.
To use this utility, follow these steps:
Step 0: Finish the simulation/assignment run Step 1: Copy “link_statistics.exe” to the data folder Step 2: Prepare the input file – LinkStatInput.dat. This file contains information needed for the program to produce the outputs. In the example below, the user specifies to output statistics for 1183 links. The statistics are written for each 30-min period. The second line and onward are the from-node (A-node) and to-node (B-node) for each link of interest.
Two output files are generated: LinkStatOutSpd.dat and LinkStatOutVol.dat As the example below shows, each line contains: A-node id, B-node id, followed by the average speed for each 30-min period.
As a post-processing procedure, this tool focuses on creating a space-time profile based on the user's choice of speed or density along a specified corridor from the results of a DynusT run. This utility creates a figure displaying a RGB color map depicting the variational, dynamic traffic conditions along the specififed corridor. This provides a great deal of information pertaining to corridor scenarios (such as evaluating mitigation strategies, road enhancements, and indicent/workzone management) and the dynamic variations in traffic conditions in response to scenario adaption along a spatio-temporal stage.
The utility currently runs in the MATLAB computing environment. The user-setup input datails edited on an Excel spreadsheet are displayed in the figure below. This spreadsheet is provided with the utility package. The spreadsheet tab titled “ScenarioSetup” requests the scenario start time, end time, AM or PM, corridor direction, the desired figure title, and the profile type (speed or density). The second spreadsheet tab titled “LinkList” requests the from and to nodes of each link within the corridor being evaluated. Note that the list of links must be in sequential order as the tool will create the figure based on the listed links if the given links exist in the dataset.
The MATLAB-based utility, when running, will ask for the location of the Excel Spreadsheet, then will ask for the location of the interested scenario's dataset folder by requesting “network.dat”. Lastly, the tool will ask for the desired location of the output file. The utility will then read the speed/density output file from the DynusT scenario run and place the created plots into the requested output folder. Given below are sample figures of both speed and density time-space profiles.
DynusT simulation result dataset, user defined parameters.
Arrival curve, or cumulative arrival curve, for vehicles that depart from user defined subset of zones, or all zonal pairs.
Sometime vehicles departing from particular areas are of special interests, for example, evacuation vehicles involved in hotzone area. This utility provides arrival/cumulative arrival time distribution of these vehicles. If running multiple scenarios, the generated arrival curve/cumulative arrival curve is helpful to compare delay time between scenarios.
There are three executable modules to perform task. Module1.exe and Module3.exe are compiled from Matlab, whose execution may require Matlab environment. Module2.exe is compiled with Python 2.5.
Module1 starts with prompt messages
“Are you interested in vehicles for all zones or subset of zones? Press 1 for all zones, press2 for subset of zones  or ”,
press number and enter. If 2 is selected in this step, the user needs to prepare a .txt file that indicates which zones are of interest. The data structure of .txt file is shown in the figure below, the number in each line(each line consists only one number) is zone ID.
The program follows with another prompt message
“You want to plot Arrival Curve or Cumulative Arrival Curve? Press 1 for Arrival Curve, press 2 for Cumulative Arrival Curve  or ” ,
press number and enter. Note that the program must accept numbers either 1 or 2. The next program gives a pop up window inquiring about the dataset directory of DynusT. If the user presses 2 in the first step, another pop up window inquires about the user defined zone subset file. Select the prepared .txt file, then run module2.exe.
Module2 reads parameters defined above from “temp.dat” and processes the simulation data of DynusT. This may require some time, depending on the size of dataset. After Module2 completes, the system generates the output file named “data.dat”. It records analyzed data in three columns. The first column is time (seconds by default), the second column is the number of vehicles arriving to each destination at time intervals, the third column is cumulative number of vehicles reaching the destination. For example, in the following figure the first value of 8 means at time clock of eighth second, the second value of 7072 indicates that 7072 vehicles arrive at their destinations during time 7th to 8th seconds, the third value of 120709 means total there are 120709 total vehicles have arrived at their destination from the beginning of the simulation to 8 seconds into the simulation. Note that if the user chooses 1 in the first step, the number of vehicles refers to vehicles departing from all zones (everywhere); if the user chooses 2 in the first step, the number of vehicles refers to those that depart from zones defined in the .txt file.
Next: draw the plot. Run Module3.exe, the system will draw the plot automatically.
In the editor drop down menu there are seven modes for visual modeling output; density, speed, queue, vehicle, volume, and travel time.
The Editor drop down menu allows the user to make changes to the simulation model, as shown below. Any changes that are not made in the input files must be changed in the editor menu. In the editor mode any physical change may be made to the model.
Under the Editor drop down menu is the item titled density. Density allows the user to view the density of vehicles on the simulation model once it has been run. As can be seen below, links with red have more than 45 vehicles and green has less than 11, colors range in between. The different colors show the different Levels of Service according the the Highway Capacity Manual, with the green meaning level of service A, and so on.
Density can be used to visualize where congestion exists. If comparisons were made of a model with a new bridge and the baseline whichever simulation shows more red would be more congested.
The density can also be read in a graph by double clicking on the link in question, shown below. The green vertical line shows the current time in the simulation. On the graph the red line shows the level of the density on that link over time in vehicles per mile per lane.
The speed mode shows the average percent of the total speed given for the link. The percent of the speed can be approximated by what color they are in the simulation model. When the link is green this shows that the traffic is going 90% of the given speed. By double clicking on a link the speed over time will be shown in miles per hour.
The queue length under the editor drop down menu approximates the length of the queue on any link. The red areas show the length of the queue. The graph can be seen by double clicking on the link of interest. The GUI output graph shows the percentage of the link that is queued over time as can be seen below. By zooming into the model the red dots that represent the length of the queue can be observed to change as the queue gets longer or shorter.
The editor menu also contains a vehicles mode. This shows the cars on the simulation model as green dots. The green dots are the actual number of cars on each link during that time in the simulation. In the GUI the cars may not seem that they are moving or that they appear just appear on a link. DynusT is a mesoscopic simulation tool that gives a general idea of where the cars are, which is why the cars may not appear to be moving or may jump. Double clicking on a link will give a graph of the vehicle density per lane.
Volume shows the volume on the links. The volumes may be estimated by color in the GUI. The links that show as green have less than 1000 cars per link. As the color changes according to the link volume chart, the number of cars increases. In the volume display window the units are in vehicles per link. Double clicking on the link gives a graph of the volumes on that link in vehicles per hour over the time of the simulation. When opening the graph make sure the MOE is set to volume.
Each of the above options can be graphed along the same path or in opposite directions. For example, to compare one link to the link that follows it and compare densities, double click on the first line then hold down the control key and click on the next link. This can be repeated as many times as necessary. The links will turn pink to show they have been selected. The graph that is created shows each link over the time of the simulation run. From this the different values of density or speed decrease in links that are attached can be compared at the same time. This could be used to see where and at what time the traffic begins to become congested.
To compare the traffic on a two-way link, double click on one side of the two-way link, hold down the control key and click on the other side of the two-way link. The graph that is created in the GUI shows a line for each direction at the time of the simulation. For example this can be used to compare the speeds on northbound versus southbound traffic.
For example, in the above side-by-side comparison, the link between two nodes in the baseline has been changed from an arterial road to a highway. Both scenarios can be viewed in the density mode simultaneously, to see if changing the arterial road to a highway relieves congestion in the following figure.
In the above side-by-side it can be seen that the density was significantly decreased in the test scenario by changing the arterial to highway between the two nodes (blacked out inside the red boxes above). This is an example of ways that side-by-side comparisons can be useful in predicting the best solution.
Side-by-side comparisons may also be used to graph the difference in densities or speeds (or any mode listed above) on one link that occurs within both scenarios. To show the both links on the density graph double click on the link in one of the scenarios. Then hold the control key and click on the same link on the other scenario. Both links will turn pink to show that they have been selected. The graph that is created in the GUI shows the line of that link in each scenario over time, to compare them to one another, during the same time in the simulation.
The MOE Time Series Window is the graphical interpretation of link and network simulation results. When the network display is in any MOE display besides in Editor mode, the user may simply double-click a link to open the MOE Time Series Window. Also, the user may click on the “Plot MOE Time Series” button on the icon menu bar when a link is highlighted in the network.
The following choices can be made from the drop-down menu of the MOE Time Series Window:
Density vhc/hr/ln\\The density graph represents the different densities on pertaining link(s). In the MOE Window the user may change the start time and end time shown on the graph, as well as the maximum value for y.
The speed graph represents the speeds traveled by the vehicles on each link. The start and end times shown on the graph, as well as the maximum value for y may be changed. In the figure below the vehicles all maintain approximately 40 mph until the model has reached about 60 minutes into the simulation.
Queue Length %
The queue graph represents the length of the queue on each link as a percentage of the total length of the link, as discussed in the previous sections. The start and end times shown on the graph, as well as the maximum value for y may be changed.
The volume MOE window shows the volumes on the links in vehicles per hour over the simulation time. The values of x (start time and end time) and maximum value of y may be changed.
# of Vehicles in the Network
The number of vehicles in the network MOE window shows the total number of vehicles that are in the network at each moment in time. When the slope of the line is negative it means that no more cars are being entered into the model, or that the number of cars leaving the model is greater than the number of cars entering the model. The values of the start time, end time, and maximum y may be changed.
# of Vehicles out of the Network
The number of vehicles outside of the network MOE window shows the total number of vehicles who have left the model. This graph will always have a positive slope. The values of the start time, end time, and maximum y may be changed.
Network: Departure Time Pattern (# of veh)
The network departure time pattern in number of vehicles, is the number of vehicles being released into the system each minute.
Network: Avg Travel Time (min)
The average travel time in the network in the MOE window shows the value of the average length of travel time per vehicle at each instance, over time in minutes.
Network: Total Toll Revenue (dollar)
The network total toll revenue in the MOE window show the total tolls on the links selected. The green line shows the dollars per minute in the simulation.
Network: Avg Generalized Travel Time (min)
The Average Generalized travel time = the average travel time + value_of_time * experienced cost.
Impacted: Avg Travel Time
This graph shows the travel time for vehicles when there is an incident in the model that causes some impact to the vehicles.
Impacted: Avg Toll Cost Per Vehicle (dollar)
Impacted: Avg Generalized Travel Time (min)
The average Generalized travel time = travel time + value_of_time * experienced cost. This is based on the case where there is an incident that has an impact on traffic.