GENERAL FEATURES
The genetic algorithm is a random guided search, capable of intelligently tracking down the global optimum solution. As with the human race, the weakest candidates are eliminated from the gene pool, and each successive generation of individuals contains stronger and stronger characteristics. It’s survival of the fittest, and the unique processes of crossover and mutation conspire to keep the species as strong as possible.
The genetic algorithm tends to require longer running times on the computer when compared to other optimization techniques. However, the genetic algorithm can be easily customized by specifying the “number of generations”. To quickly obtain a reasonable timing plan, specify a small number of generations. To obtain the global optimum solution, specify a large number of generations.
- Link curvature
- Printing support
- Dynamic scrolling of the map
- Drag and drop nodes on the map
- Zoom in, zoom out, pan, show all
- Graphical add/delete of links/nodes
- Select and move entire groups of nodes
- User-friendly bitmap background scaling
- Right-click on nodes to edit their properties
- Nine available map background colors to choose from
- Progression routes drawn with bold lines for emphasis
- Right-click on a node and “View Report” for this node
- “Undo” feature for canceling recent changes to the map
- Right-click on a node and “View HCS results for this node”
- View intersection names by moving the mouse pointer over a node
- Right-click on a node and “View CORSIM animation for this node”
- Define progression routes automatically by selecting a group of nodes
- Ability to underlay user-supplied bitmap backgrounds and aerial photos
- Display level of service on the map for TRANSYT, CORSIM, and HCS
- Graphical coding of progression routes, arterial weighting factors, and route titles
- Copy-and-paste intersections, to avoid re-coding lane configuration, volumes, and timings
- Link lengths, free-flow speeds, link names, gridlines, intersection delay and LOS on the map
TRANSYT-7F offers CORSIM post-processing, such that the engineer can summarize results from one or more CORSIM runs (with varying random number seeds). Following a CORSIM post-processing run, TRANSYT-7F produces a summary text report that contains NETSIM link results, NETSIM node results, and CORSIM network-wide results. TRANSYT-7F can also provide a one-page formatted report for NETSIM intersections. The summary text report and formatted report both provide intersection-wide control delay and level of service. The formatted report also provides approach-specific control delay and level of service. The Map View can also be used to graphically display NETSIM control delay and level of service. The interactive time-space diagram can be used to observe and design bandwidth in NETSIM.
TRANSYT-7F also offers “direct” CORSIM optimization (also known as “microscopic” optimization) of cycle length, splits, and offsets, using the genetic algorithm. With direct CORSIM optimization, TRANSYT-7F applies the genetic algorithm to supply timing plan candidates, and CORSIM evaluates them through its own simulation. The end result is a new copy of the original CORSIM input (*.TRF) file containing the optimized timing plan, plus the availability of TRAFVU animation for the optimized timing plan. TRANSYT-7F will minimize NETSIM control delay by default, but the user can choose among nine different CORSIM MOEs to be used as the optimization objective function.
Because direct CORSIM optimization is accomplished via genetic algorithm, this ensures that the user’s original timing plan will be improved upon, assuming that a better timing plan exists. In addition, direct CORSIM optimization can be easily applied by anyone, because there is no learning curve. Simply launch TRANSYT-7F, load any TRF file, select one of the nine available optimization objective functions, and click on “Run”. This alone achieves a better CORSIM timing plan than any other program or process. Once the user gains experience with choosing non-default genetic algorithm parameters (e.g., mutation probability, population size, etc.), the optimization process can become even more efficient and effective.All pre-timed, fully-actuated, and semi-actuated intersections in CORSIM can be optimized directly. The current version of TRANSYT-7F does not support direct CORSIM phasing sequence optimization, although this could be accomplished by macroscopic (TRANSYT-based) optimization. If an optimized phasing sequence is coded or exported into a TRF file, the overall timing plan could then be further improved via direct CORSIM optimization of cycle length, splits, and offsets. Note that direct CORSIM optimization may not be practical for large TRF files, due to the CPU running time required for microscopic simulation.
TRANSYT-7F has the ability to import existing CORSIM input files. However, if no CORSIM file exists yet, TRANSYT-7F also offers “one-touch” CORSIM animation (i.e., CORSIM file export). This pre-processing feature creates NETSIM networks from scratch, and is available for either the entire TRANSYT-7F network, or for individual intersections. To create a CORSIM input file that reflects an entire TRANSYT-7F network, click on the “CORSIM Animation” icon on the TRANSYT-7F toolbar, or select “File > CORSIM > View animation for this network”. To create a CORSIM input file that reflects one intersection only, simply right-click on an intersection in the Map View, and select “CORSIM > View animation for this node”. If the user doesn’t wish to view animation, CORSIM input and/or output files can optionally be generated without launching animation.

- direct CORSIM optimization
- conversion to macroscopic TRANSYT analysis
- post-processing of CORSIM’s own simulation results
- time-space diagrams that reflect CORSIM’s own signal timing
- formatted reports that reflect CORSIM’s own simulation results
- superimpose CORSIM’s own intersection-wide control delay and level of service on the Map View
Highway Capacity Software (HCS) data files can now be loaded directly into TRANSYT-7F, provided that they are available in *.XHS (XML for HCS+ Signals) format, or *.XHI (XML for HCS+ Interchanges) format. There are two possible methods for loading HCS files into TRANSYT-7F. The first method involves simply loading an HCS file by selecting File > Open from TRANSYT-7F. This will automatically generate a corresponding TRANSYT-7F data file for the HCS intersection(s). The second method involves appending HCS intersection data to an existing TRANSYT-7F (*.TIN) input file. First, it is necessary to open the existing TIN file with TRANSYT-7F. Next, it is necessary to select File > Open and open an existing file of type *.XHS, which will enable the “New Node Number” dialog box. This is the node number that will be used inside the TIN file. After selecting the new node number, the new data will automatically be added to the TIN file.