VISSIM 5.30-05 User Manual

6 The Traffic Network
When an elder VISSIM network file is read from file, the *.SIG files are
created automatically.
The *.SIG files and the VISSIM network file *.INP need to be stored in the
same directory.
*.WTT files are automatically loaded. They are not subject to changes.
● Program no.: Select the signal program for the simulation. The signal
program can also be a Daily Signal Program List, cf. section 6.7.4.8.
In the single-step mode, the program can be switched during simulation.
If the new signal program number is confirmed via OK, the program will
be switched in the next simulation second.
● EDIT SIGNAL CONTROL: Via this button, the Signal Control Editor is called,
cf. section 6.7.4. The signal groups need to be defined and can be
deleted in the SC Editor. Changes to the channel number of existing
signal groups are recognized in VISSIM and will be adjusted in the
appropriate signal heads.
Since VISSIM 5.20, the Controler Frequency is read from the external
control data.
Internally, the controller frequency is the least common multiple of all SC.
The value may not exceed 10, since VISSIM permits ten simulation steps
per second at most.
● START OPTIMIZATION: Click this button to start the greentime optimization
of the current stage-based fixed-time control, cf. section 6.7.3.11.
6.7.3.11 Greentime Optimization of Stage-based Fixed-time Control
This functionality requires the VISSIG add-on.
This functionality “automatically” improves the goodness of a signal plan for a
single VISSIG signal control.
For that purpose, VISSIM runs repeated simulations of the whole network
with all controllers switched off except a single one. Thus, upstream signals
have no effect. The simulations continue as long as changes of the stage
green times increase the flow (total volume) or reduce the average vehicle
delay. Alternatively, the user can stop the iteration. The stage timings with
the best result (highest flow / lowest average vehicle delay) are saved in the
*.SIG file at the end of the optimization.
You can run the optimization either for the selected SC or automatically for
all all fixed time SCs:
► For a single SC, click the button START OPTIMIZATION in the Signal control
dialog.
298 VISSIM 5.30-05 © PTV AG 2011