This PTV Talks webinar focuses on the basics of PTV Vistro.
- Traffic Signal Setup and Geometry Refresher
- Global Settings for Optimization
- Traffic Control Workflow’s Intersection Settings
- Local Signal Optimization
- Coordination Groups
- Network Signal Optimization
- Time-Space Diagrams
Watch recording below and download the example files.
Download a demo version of PTV Vistro.
Answers to Questions Asked During the Webinar
Question: What types of signal optimization can Vistro perform?
Answer: Vistro performs local optimization (individual signals) and network optimization (corridors and network-wide).
Question: What options exist for optimizing signals?
Answer: At the local level, you can optimize the splits (choice of v/c balancing or minimizing critical delay), or optimize both the splits and the cycle lengths. Options exist to set lower and upper values for cycle lengths and to define the step-size (e.g., test cycle lengths between 60 – 150 seconds at 10 second increments). You can also define a specific set of cycle lengths to optimize (e.g., 60, 90, 120 seconds).
At the network level, you can also optimize offsets, and you can allow lead/lag optimization. You have options to optimize all the routes in your network at once, or only those that are part of specific coordination groups. The Performance Index (objective function) can be modified to factor the delay and the number of stops based on user-specified values. You can choose between using our robust Genetic Algorithm (GA) or more simplified Hill Climbing (HC) optimization methods.
Question: What is an optimization route in Vistro?
Answer: Routes are drawn in Vistro to define travel paths for the purposes of creating time-space diagrams and optimizing traffic movements along those routes. Routes are directional, and can be along straight corridors or include a series of turns along multiple roadways. Routes can also be assigned a weight, which allows preference for certain routes during the optimization.
Question: Can I still modify offsets once the optimization has completed?
Answer: Yes, you can slide the bars in the time-space diagram to adjust the offsets.
Question: What types of time-space diagrams are available in Vistro?
Answer: Vistro has the options for depicting the time-space diagrams as flowing off (flows from one signal to the next) or as arterial bands (green bands). Both can be shown as one-way or two-way time-space diagrams.
Question: Can you set a master controller/intersection in Vistro?
Answer: Yes, each signal coordination group in Vistro can have one signalized controller selected as the master controller, which locks the offset at this controller to a zero offset. When the master controller is set in the coordination group menu, the offset value at this intersection is set to zero, and all other signal controllers in the coordination group are automatically calculated relative to the master controller (if previously set).
Question: Can the optimized timings from Vistro be imported into Vissim?
Answer: Yes, from Vistro you can export to Vissim ANM, which creates an *.ANM of the network and individual *.RBC files for each signal. You then import those into Vissim. Once you have the network in Vissim, you can use any updated signal timing data (optimized, reflecting different times of day, etc.) you export from Vistro, which is contained in individual *.RBC files for each signal.
Question: Can Vistro model networks with left-hand side driving operations?
Answer: Yes, you just need to be sure to first toggle the direction of traffic field in the global settings menu to the left-hand traffic option prior to building your network in Vistro.