10.1.1 Analysis Sets
When you start a new file, the file contains a single Analysis Set. You can rename it by locating it in the Analysis Sets section of the Data Outline and then using the Data Editor to set its properties.
Although
you can store multiple Analysis Sets within one file, only one set of
results is stored at any one time, representing the results from one
Analysis Set. To run different Analysis Sets, you must select each in
turn via the Analysis Set drop-down menu and run it separately. You
can however use the Run>Run All Analysis Sets and Generate Report
option to run all Analysis Sets that have their Include In Report
option set.
As an example, add a new Analysis Set (via the Data Outline), and note that the drop-down menu at the top of the main TRANSYT window now lets you choose between two Analysis Sets. Now use the Data Editor or Main Data screen to view the network cycle time; note that the network cycle time has an icon next to it to indicate that it can be set for each Analysis Set. Set the network cycle time to 100s. Switch to the other Analysis Set via the drop-down and notice that the network cycle time is now the value for the other Analysis Set.
For each Analysis Set, you must enter a Demand Set (e.g. enter 'D2' to use Demand Set 2). This determines the flows that will be used for this Analysis Set. E.g. you may set up two Analysis Sets with the same signal plan but different Demand Sets (representing two different traffic forecasts, say), a third Analysis Set that uses a Demand Set which includes extra development flows, and then a further two Analysis Sets using the same Demand Sets but alternative signal plans or network cycle times.
(In more complex scenarios it may of course be easier simply to save the different setups as different files.)
The data items that can be entered for each Analysis Set are easily identified within the data
О
editor by the 'card stack' symbol on the screen.
10.1.2 Demand Sets
When you start a new file, the file contains a single Demand Set. You can rename it by locating it in the Demand Sets section of the Data Outline and then using the Data Editor to set its properties.
Each Demand Set defines a separate set of flows, but the flows themselves are entered using the normal data entry screens. This applies to OD Matrices as well, i.e. an OD-Matrix provides access to define the OD flows for several demand sets.
If you need to add together multiple sets of flows, add a new Demand Set and tick the Composite option; you can then enter the Demand Sets that you wish to add together to form this new Demand Sets - e.g. enter "D1,D2,D3" to add together the flows for Demand Sets 1-3. A Demand Set cannot refer to itself in this way, so you must always add a new Demand Set for this purpose. If the currently selected Demand Set is composite in this way, then link flows for individual links will be greyed out and will show the calculated total flow, as in the screenshot below.
To run a particular Demand Set, you must select an Analysis Set that uses that Demand Set. Changing the Demand Set on the main drop-down menu at the top of the main window does NOT select that Demand Set for running, it only selects it for data entry. E.g. if you have three Demand Sets and wish to run each in turn, you must also set up three Analysis Sets.
Warning
Use
the Start Time option to enter a time of day that the flows are for.
(This is only used for labelling purposes when showing time
segments.)
The
Total Flow and Uniform Flow for each link can then be entered
separately for each Demand Set, using the Data Editor and/or Data
Grids.
Locking Analysis and Demand Sets
'
In Analysis Set and Demand Set definitions, tick the Locked option if you have finished entering data for the set and want to avoid accidentally altering data. In this mode, all relevant data fields will be locked when this set is chosen. For example: create two Demand Sets, and lock one Demand Set only. Now open the Flow Allocation Tool: the entry flows for the locked demand set will be greyed out and disabled, but editable for the other demand set.
Although locking an Analysis set locks all signal timings, it does not prevent the timings to be changed by carrying out an optimised run. Furthermore, locking an Analysis set does not lock the data of the referenced demand set.
10.1.4
Time Segments
By
default, a TRANSYT uses a single time segment which is the same
length as the entire modelled period. You can view and edit this via
the Data Editor (Network Options>Network Timings section) or via
the Main Common Data screen. By default, there is a single time
segment of 60 minutes, giving a total modelled time period of 60
minutes.
To
split the 60 minute period into 4 time segments of 15 minutes each,
simply edit the Time Segment Length and Number of Time Segments
values.
Time varying traffic flows are specified only on entry links which allow flows to propagate through the network. (See section 11.1.1)
After running such a file, the Time Segment drop-down menu at the top of the main window will show an entry for each time segment, plus a special Summary item. Displaying any set of results (network results, or results for individual links) will then show the results for the chosen time segments. You cannot see all time segments within the Data Outline or on one screen together, but generated reports can optionally show results for all time segments.
TRANSYT 13 - c:\lmport of TRL1 .tl 3
j Analysis Set 1 - (untitled)
Demand Set 1 - (untitled)
NetCon
S c:\ImpartafTRLl.tl3
File Description
@ Analysis Sets ffi Demand Sets В TRANSYT Network S Network Options
ffl- Routes
Node Optimisation Order
Network Results (08:15-08:30)
Summary
Stops And Delays
Data Editor
Sum ma 17
Time Segment [08:00-08:15) [Time Segment [08:15-08:30)
(Network Results (08:15-08:30}} ITime Segment
Calculated Flow Into Link (PCU/hrl
Adjusted Flow Warning
Calculated Sat Flow (PCU/hr)
Jeg
Of Saturation (%)
DOS Threshold Exceeded
Effective Green (s (per cycle}J
Queues And Blocking
Unweighted Performa
Fuel Consumption
Performance Index (£ per hr)
Default Values
Unable to add
Unable to delete
The Summary time segment represents an overall set of results for the overall modelled period. Results are aggregated in various ways (some are summed, others are averaged, a few are weighted by flow, etc.); you can check these by using the Help>Glossary Screen option and clicking on any result in the Data Editor.
Please
note that the "Best PI" reported in the "Running
Calculation" dialog and the Summary Results P.I. will not match.
This is because the "Best P.I." value reported is always
the value used by the optimiser which is the TOTAL P.I. of all of the
time segments combined. The value shown in the Network Results screen
will be either the AVERAGE P.I. of all the segments or the value of a
currently selected time segment.
|
Summary Results |
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I! rsl |
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Last run: 03/09/2010 16:13:51 |
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Analysis Set Used: A1 - (untitled) |
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Run Data Present: Present |
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Cycle Time Used: |
92 |
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Network PI: |
334.24 £ per hr |
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Network PI (unweighted): |
313,33 £ per hr |
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Network average speed: |
16,71 kph |
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Total network delay: |
22.5 PCU-hr/hr |
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Highest DOS: |
60,19% (T5 21/1) |
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Number oversaturated: |
0 (0%) |
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Network within capacity: |
YES |
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1In the Data Outline select any link and then in the Data Editor select Length. Then select Link Flows>Total Flow
2Select the Stage Library tab. Click "Auto Generate Stages". This will generate a set of valid library stages, each of which maximise the number of phases that can run in them.
3When creating additional Locations, select which OD matrix it will apply to first, then click or drag the Location icon
4If you have dual monitor display, either right-click in a blank area of the network and unselect Tools>Keep NetCon Inside Application Window each time you open NetCon, or set your preference via the main Preferences screen. The NetCon window will then become detached from the main TRANSYT window and you can position it on the secondary monitor.
TRANSYT 14 User Guide (Issue J)