Junctions Version History

Modelling and analysis of roundabouts, priority junction and signalised junctions

Junctions 9 is the latest version of TRL’s industry-standard package for modelling roundabouts, priority junctions and simple signalised junctions.

Area Enhancement
PRODUCT Enhancement: Now a 64-bit application, offering better memory management and hence resolves issues where more memory is needed such as the use of highresolution background images in the Junction diagram
MODEL Enhancement: HCM roundabout simulation model, offering the option to use the HCM capacity model in conjunction with Simulation ModeThis offers the ability to model junctions close to capacity and over capacity for the first time, as well as those with time-varying traffic demand
MODEL Fix: HCM Proportional Lane Demand division (non-sim) now working as intended 
MODEL Improvement: Demand dependency: Now allows controller to continue to run same stage when there are two or more adjacent intermittent stages
UI Improvement: SAVED files are added immediately to “Recent files” list 
UI Fix: Measuring tool – Minor Road visibility component no longer annoyingly moves the schematic
UI Fix: Switching from Vehicles to PCU now correct for bypasses in HCM 
UI Fix: Phase Timing Diagram – Phase order now matches that of the Data Outline 
UI Fix: copy-paste of a DataGrid now works for customised DataGrid 
REPORTS Enhancement: Vector diagrams replaced with high-quality bitmaps, offering improved quality of PDF reports and more control over the resolution of report images
REPORTS Fix: Content links within Report Word Document now working 
VARIOUS Fix: Several other small fixes have been implemented in this release
USER GUIDE Revised User Guide (Issue G):

  • Details added on new Highway Capacity Manual (HCM) roundabout simulation model
  • Recognition of change of Junctions 10 to a 64-bit application
  • References made to new resolution options for bitmaps in reports
Area Enhancement
MODEL Enhancement: Calculation of arm RFCs and DoS values while in Lane Simulation mode
MODEL Enhancement: Modelling the effect of the presence of cyclist on capacity, using dual PCU factors
MODEL Enhancement: New VA option that adds a delay to signals triggering an ‘absent demand’ event, to better represent best-practice controller configurations
LICENSING Enhancement: Login requirement now 21 days instead of 7 days
MODEL Fix: Issue with ‘Obstruction’ in a network with linked junctions is resolved
MODEL Fix: ‘Stage skipping’ and implicit ‘all-red’ stage options now functioning as intended
MODEL Fix: Simulation – ‘vehicle getting stuck near crossing’ issue is resolved
UI Fix: Issue with the copy/paste facility, between turning counts and OD screens in J10/T16 and for left-right staggers both resolved
UI Enhancement: Alternative method of panning in diagram, without use of middle mouse button/wheel
UI Enhancement: Newsfeeder – links now open in default browser
UI Fix: Oddity with diagram’s scale ruler resolved
RESULTS Fix: ‘Max stage duration’ and ‘Mean phase duration’ now correctly calculated
RESULTS Fix: Reports now generated quicker after removal of unnecessary processing
VARIOUS Fix: A number of other small fixes have been implemented in this release
USER GUIDE Revised User Guide (Issue F):

  • Changed to reflect minor changes associated with this release,
  • e.g. added references to the new cyclist modelling capability, as well as the calculation of RFCs in Lane Simulation
  • plus additional advice on hatching and white lining
Area Enhancement
LICENSING Organisation (company) name shown in both the TRL Software Portal and in the Licence Information screen within Junctions 10
UI/PORTAL Enhancement: From within Junctions 10, access to cloud-based ‘guest’ files that are shared with you by other organisations
UI Enhancement: Reduced chance of reports failing to save to your chosen location due to too long a path length. Additionally, a new ‘File Preference’ allows users to direct Junctions 10 to save HTML reports to their ‘temp’ folder
UI Blue file selector controls at the bottom of the screen now shows full filename in preference to attempting to show location too. Full path shown as a tooltip instead
UI Fix: Data Field Finder can now optionally show “Advanced” data items as well as being more reliable in what it shows
UI Fix: Top menu drop-downs now show more Demand Sets, Analysis sets and time segments without having to scroll
UI Fix: A number of other small fixes have been implemented in this release
USER GUIDE Revised User Guide (Issue E):

  • Changed to reflect minor changes associated with this release,
  • e.g. added references to the new access to cloud-based “guest” data files from within the main Junctions 10 application
Area Enhancement
LICENCE Enhancement: Ability to lock licence to a device so that Junctions 10 can be used off-line (No internet)
LICENCE Improved tolerance of poor internet access: It tolerates short outages better
PORTAL Enhancement: The ability to offer either “read-only” or “contributor” access to files and folders within your file directory area, facilitates close collaboration with client
UI (Fix) Excel demand set source “offset” ignored when it is meant to be
USER GUIDE TRL Software Portal’s User Guide updated to include full details of the new collaborative “guest access” facility
USER GUIDE Revised User Guide (Issue D):

  • Changed to reflect minor changes associated with this release, e.g.
  • Details of new “off-line use facility added 
  • Details of new “guest access” facility added  
Area Enhancement
UI Enhancement: New ‘File Preference’ added to allow easy switching between the two licensing systems – CLOUD (user-based) and ERIS (device-based)
UI Enhancement: ‘No give-way’ roundabout arms no longer treated automatically as entry-only – Can now be two-way
UI Fix: Issue with number of background images that could be loaded is resolved
MODEL Fix: ‘Use circulating lanes’ crashes when in simulation is resolved
REPORTS Report correctly lists custom intercept adjustments (No longer repeats first adjustment)
DOCS Updated EULA to include ‘fair use’ description for user licence allocation
USER GUIDE Revised User Guide (Issue C):

  • Changed to reflect minor changes associated with this release
Area Enhancement
UI Enhancement: New message to inform users when there is a need to log out and in again, such as when licencing entitlements have changed will logged into the desktop product
UI Fix: Minor fixes to the cloud load/save options
UI Fix: Labelling of major road “width of carriageway” components when two components are used – Changed to match the labelling of these components in the user guide, i.e. W1+W3, and W2+W4
UI Fix: Major road measurement calculation with respect to 2 and 4 measurement components
MODEL Fix: Vehicle actuation – Inter-stages now consistent when stage skipping occurs
MODEL Fix: Additional checks added when using intermittent stages, such as checks on whether any banned stage transitions affect the simulation run. If so, simulation is stopped, and an error message issued to the user
UI Fix: Calculation of phase lags no longer prevents the file status going to green, to indicate that it is up-to-date
MODEL Fix for OSCADY opposition ECO / LR scenarios
UI Various minor/trivial cosmetic fixes to the user interface
DOCS Revised User Guide (Issue B):

  • Changed to reflect minor changes associated with this release
  • New section added, covering Splitter / Merge junction types
  • TRL Software Portal: List of supported internet browsers added

Please see the main Junctions page for details about the new features in Junctions 10.

Area Enhancement
Model Fix: No longer crashes when using “Use circulating lanes” in simulation mode
Area Enhancement
REPORTS Fix: Report no longer crashes if it contains the Junctions Diagram (This issue is often associated with newer laptops and with an Intel(R) HD Graphics Card Renderer)
FEATURE Enhancement: Export to TRANSYT extended to include export of key ARCADY and PICADY data, including geometric data
FEATURE Enhancement: Anonymous feature-usage analytics system added – This facility helps us to develop better software by establishing what features are more heavily or more lightly used, without capturing any personal data
UI Enhancement: New user preferences:

  • “Show arm names in new files”;
  • “Start time for ONE HOUR profile (AM) (hh:mm)”
  • “Start time for ONE HOUR profile (PM) (hh:mm)”
UI Enhancement: Summary results screen: Formatting of analysis / demand set names can be achieved as it now responds to any HTML or CSS in the analysis/demand set name
UI Enhancement: Summary Results: Set IDs (in addition to their names) reported
MODEL Fix: OSCADY module “Unable to Calculate Random Queue” crash now fixed
MODEL Fix: Lane sim: storage is now set correctly when exit lane is linked but not entry lane
MODEL Fix: Small improvements to lane sim ORT and mutual opposition
REPORTS Fix: Report no longer crashes if you close report window whilst generating PDF file
REPORTS Fix: Report no longer crashes while in lane sim mode, if arm name contains an ampersand
UI Fix: Ability to step to next/previous time segment restored
UI Enhancement: Improved speed of analysis/demand/result set switching
UI Fix: Some minor UI changes relating to accident prediction
DOCS Revised User Guide (Issue E) – Revised to reflect minor changes associated with this release.  Bypass advice revised
ALL Various other fixes and minor enhancements.
Area Enhancement
Addition of OSCADY module for signalised junctions.  More details
MODEL Lane simulation: circulating lanes at roundabouts can now be modelled (including signalised cases, if OSCADY module is registered)
MODEL Lane simulation: most files should run slightly faster
MODEL Lane simulation: fixed bug where model would crash if lanes have non-integer storage
UI New File>Export>Save without results option allows file to be saved with time segment results etc stripped out, allowing for a smaller file size.  (Results must be re-generated when file is subsequently loaded.)
UI Fixed bug where user guide PDF would sometimes not open (was dependent on PDF reader)
UI Fixed bug where lane simulation movements grid not usable at 125% DPI
UI Data Editor and Data Grids now use a non-bold font. Previous appearance can be restored by changing File>Preferences>Appearance>Windows Font Bold
UI New “Sync” button on main toolbar will set the Data Outline position to the item containing the last clicked-on data field
UI x-y graphs: if the graph is stopped, the last point is discarded rather than being given a value of zero.
ALL Various bug fixes and minor enhancements.
Area Enhancement
MODEL Lane Simulation: capacity restrictions can now be applied to both entry and exit lanes. A “bottleneck” type of pedestrian crossing with a fixed capacity can be used to do this. In this way it is possible to model cases such as a two-lane roundabout exit that narrows to one lane a short distance from the roundabout. For more details please see Section 14.8 of the Junctions 9 User Guide.
MODEL Lane Simulation: results are now available for each movement within each lane. Access these via the ‘Movement Results’ option in the Options tab of the Lane Simulation screen. For more details please see Section 14.4.2 of the Junctions 9 User Guide.
MODEL Lane Simulation: fixed bug where model would crash if no movements are possible
MODEL Lane Simulation: changed the way turning proportions and HV proportions are handled at linked junctions. (Previously certain files would sometimes fail to run.) This change is mostly transparent to users but may produce slightly different results.
MODEL PICADY results now show total demand and queueing delay etc in the ‘Total’ row of data grids in the UI.
MODEL Queue percentile results would sometimes show zero at high flows; they now show the existing upper-bound of 200 instead.
MODEL Lane Simulation: the user is now prevented from changing Analysis/Demand Set or adding/deleting items during a simulation run.
MODEL Fixed problem with Veh/PCU conversion with HCM TWSC/AWSC junctions
MODEL Major road width for PICADY junctions previously had a minimum of 6m. Widths down to 4m can now be entered, although a warning will be shown to emphasise that these are outside the range of the original research. (For one-way junctions, the minimum width is 3m.)
MODEL Demand Set Relationships: if using ‘advanced’ relationships, the resultant values now take into account any flow scaling factors on the constituent demand Sets.
MODEL HCM Roundabouts now use calibration factors from HCM 2016 (6th edition) by default. Calibration screen now allows defaults to be restored from HCM 2010 and HCM 2016.
DIAGRAM Fixed bug that made the selection and moving of items (particularly lanes in Lane Simulation mode) unreliable
DIAGRAM HV% now shown alongside the OD demand (green arrows) next to each arm. In Edit Demand mode, the HV% can be edited directly on the diagram by double clicking. HV% display can be turned off in the Diagram Options>Text Overlays screen.
DIAGRAM Clearer distinction between priority and non-priority streams for PICADY junctions
DIAGRAM In Lane Simulation mode, a new option (Diagram Options>Other>Show lane interiors) controls whether solid white interiors should be shown for lanes. With this turned off, some of the visualisation overlays are easier to see against a background image.
DIAGRAM Easier to move arms at one-way junctions
DIAGRAM Top and bottom toolbars can be hidden using the View menu
DIAGRAM The ‘whole period results’ overlay introduced in Junctions 9.0.1 is now turned OFF by default.
TEMPRO TEMPRO link updated and tested for TEMPRO 7, 7.1 and 7.2.
UI Right-clicking the Data Outline or Data Editor buttons on the main toolbar will toggle the active screen (if any) from one type to the other. E.g. if you press the Geometry button on the vertical toolbar to show geometry for Arm 1 in an Data Editor, then right-clicking the Data Grid button will switch to show geometries for all arms in a Data Grid, without creating any additional windows.
UI Run menu and auto-run option removed, to simplify UI.
UI Selections within data grids and matrices can now be copied and pasted. (Previously it was only possible to copy/paste the entire grid/matrix.) To do this, make a selection and then use the right-click menu.
UI Any window can now be taken outside the main application window by double-clicking the window’s title bar. It can then be freely positioned on a second monitor, for example. To restore the window back inside the main program window, double click its title bar again.
UI The ‘edit all’ function in data grids and data matrices (available on the right-click menu after selecting some cells) now works with checkbox and dropdown data types.
UI New File screen now allows staggered junctions to be selected.
ALL Various minor bug fixes and enhancements
Area Enhancement
REPORTS Export to Word
has been improved
REPORTS Most reports are
quicker to generate
REPORTS A smaller font is
used by default.  This leads to more
compact but still readable reports.  If
you prefer the original font size, you can restore it by changing File>Preferences>Reports>Font
Size for Reports.
REPORTS ‘Turning
Proportions’ and ‘Average PCU per Veh’ tables are now only printed if the
‘Detailed Demand Data’ option is ticked.
(File must also be in Advanced Mode.)
REPORTS If the Input section is ticked, then the Traffic Demand section is
automatically ticked and cannot be turned off.   This is to prevent cases that have been
described to us where reports have been submitted which include all inputs
and results other than turning proportion grids.  Such incomplete reports can potentially
conceal discrepancies between the entered turning proportions and the results
shown in reports.
REPORTS Various minor changes to appearance,
column widths, justification etc
.   Reports
will tend to be neater than in previous versions when using the ‘Show arm and
junction names’ display option.
REPORTS If using a single
Analysis Set and multiple Demand Sets, the second Demand Set onwards now
omits the superfluous headings for Geometries etc.  With large files this leads to shorter
DIAGRAM For roundabouts, a new data overlay shows whole period
(as shown in the Summary Results screen) next to each arm.   This is turned on by default but can be
switched off by clicking Overlays>Whole
Period Results.  Adjust the
size/position via Options>Text
overlays>Whole period results.
The overlay uses the same colour coding (both background and
foreground) as the corresponding Summary Result screen items.
DIAGRAM If working with
multiple junctions, the junction ID size can now be altered independently (Options>Other>Junction ID Size)
DIAGRAM When exporting as
a bitmap (right-click and use the Export menu), it is now possible to enter a
desired resolution.  This can be used
to generate large high quality bitmaps.
DIAGRAM Geometry
measurement tool:  for some
measurements you can now right-click on a control point to add more control
points, giving finer control over the
curvature of the construction lines.
UI Summary Results
screen:  a new item in the Show menu provides a shortcut to the Sorting and Display section of the
Data Outline where various options can be set.
UI Summary Results
screen: priority PICADY streams (A-C etc) are no longer shown here.
UI A Task List
warning is now shown if the HV% is zero for all movements.
UI Header cells in
data matrices (OD screen, Veh Mix screen etc) now allow long arm/junction
names to word-wrap.  The Widths slider
in each screen can still be used to control the column widths.
UI O-D matrices can now contain negative
.  This is ignored if running the traffic
model but can be used to construct matrices for use with Demand Set
relationships where negative growth is involved.
UI Each Analysis/Demand Set can now
optionally be associated with a Colour property
Edit the colour by clicking or double-clicking on the colour when
showing the Analysis/Demand Set properties in the Data Editor or a Data
Grid.  Colours are shown in the Data
Outline and the main program dropdowns and can be used to visually
distinguish between groups of sets.
This system can be turned off via Data
Outline>Options>Sorting and Display>Colour Analysis/Demand Sets;
this option has a corresponding file preference to set its value for new
UI All demand, flow and capacity inputs and
outputs are now rounded to whole numbers
if the current traffic units areper hour.   This leads to cleaner data grids and
reports.  If working in per minute or per time segment, decimals are shown.   Decimals are alsoshown if a number
between 0 and 1 is entered in the O-D screen, e.g. when entering linked junction
turning proportions.    This behaviour
can be overridden by changing File>Preferences>Appearance>Round
flows to whole numbers.
UI If viewing PICADY
stream results in a Data Grid, it is now possible to use the Filter menu to
show only those streams associated with the current arm
UI The padlock on
the O-D screen, Vehicle mix screen and Demand screen now has a third state
that freezes the entire contents of the screen in a read-only state.
This can be used to view demand data for several Demand Sets at the
same time
.  (Show the O-D screen
for the first Demand Set, use the padlock to freeze the screen, then show a
second O-D screen and activate the second Demand Set, and so on.)  Clicking the padlock again will un-freeze
the screen.
UI The choice of traffic units for new files
can now be set
via File>Preferences>General>Default
Traffic Units / Default Traffic Units Period.
You can thus configure all new files to start off with units of
e.g. PCU/hr or Veh/min according to your preference.    Once a new file has been created you can
change the units as usual via the Data>Units
UI Analysis/Demand
Set dropdowns are wider , to accommodate long names
UI Read data from
Excel: a new option ‘Show details for
all Demand Sets’ will launch a Data Grid showing the Excel options for
all Demand Sets.  This is useful for
quickly reviewing or editing the options across multiple Demand Sets.
Calculator:  Some authorities contain
two zones with the same name.  The
calculation for such zones was correct but if subsequently editing the TEMPRO
properties, the selection would revert to the first of the two zones.  This has been fixed by appending the zone
ID to the zone name.  If editing an
existing file with TEMPRO properties you may need to re-set the zone.
Simulation:  it is now possible to
enter a Minimum/Maximum Capacity for PICADY lanes.  This can be used as a way of calibrating or
adjusting the capacity of lanes.
Please note that this should be used with caution; please contact TRL
for advice if necessary.
USER GUIDE Clarification has
been added to the User Guide to confirm that queues in ARCADY/PICADY are the
total on the arm regardless of lane distribution (UNLESS in lane simulation mode),
that they include slowly moving vehicles and that they represent expected values.
ALL Various minor
enhancements and speed-ups


Area Enhancement
Model Revised model for mini-roundabouts
Model HCM TWSC and AWSC intersections (HCM intersections)
Model Lane Simulation Mode for T-junctions
Model Lane Simulation for linked roundabouts and T-junctions
Model Lane Simulation for pedestrian crossings
UI Measuring roundabout geometries using the junction diagram
UI Stick diagram mode
UI Junction diagram: text is clearer
UI Editing Traffic Flow using the junction diagram
UI Audit Trail
UI Calculating TEMPRO Growth Factors
UI Reading Demand Set flow data from Excel
UI Edit O-D data for more than one junction at a time
UI The same O-D data can be used by more than one junction
UI Faster report generation and inclusion of graphs
UI All results colour coded to show whether they are up-to-date
UI Multiple Data Editors can be used at the same time
UI New padlock state allows freezing of the contents of data editing screens
UI Analysis/Demand sets can be renumbered
UI More control over which data fields differ between Analysis/Demand sets
UI Results for all Analysis/Demand sets stored in the file
UI Analysis/Demand sets within a file can be compared
UI Various other UI improvements
Area Change
UI Various fixes to make the importing of Junctions 9 files more reliable.   Please note that there is a difference in the way that Junctions 8 and Junctions 9 handle Analysis and Demand Set IDs.   Junctions 9 allows the IDs to be set by the user to any value, whereas Junctions 8 sets them automatically according to an internal numbering system.  If you import a Junctions 9 file where Analysis/Demand Sets have been deleted/renumbered/re-ordered, the remaining sets may appear in a different order in Junctions 8.  Any references to IDs such as Demand Set Relationships will be blanked during the import and will need to be re-entered manually in Junctions 8.  Please contact TRL for further advice if necessary.


Area Enhancement
MODEL Entry Lane Analysis Mode allows you to investigate the relative performance of alternative lane configurations at roundabouts
MODEL HCM 2010 Mode implements the HCM 2010 methodology for roundabout analysis
MODEL Options for the modelling of linked roundabouts have been simplified
MODEL Bypass and filter lanes at roundabouts
RESULTS Residual Capacity mode quantifies the ‘spare’ capacity at any junction type
RESULTS Junction results show demand-weighted delay and LoS for the overall junction
RESULTS 95th percentile queues can be shown in the Summary Results screen
UI You can choose whether or not to use Advanced Mode. If turned off, then many data items and options are hidden
UI Library Files system
UI Windows can be docked and there is a new window manager screen
UI Files can be merged together
UI Demand Set Utilities allow you to check for differences between demand sets
UI It is now easier to distinguish between original turning counts and scaled demand used in the model, and the final calculated entry flows
UI Various minor improvements to the Junctions Diagram
UI Many more minor enhancements that make data entry easier
Area Change
GUI Fixed bug that caused report to show same data for multiple demand sets
GUI Linked roundabout data now included in reports
GUI Various minor bug fixes
MODEL Various minor bug fixes

ARCADY 7.0.0 was a major release that included a redesigned GUI and many changes to both the GUI and the model.  For full details, please see the ARCADY 7 overview.

Current Version: 10.1.1 Version History

System Requirements:

Windows 10 or above

Supported Browsers (Portal only):

Google Chrome (latest version)
Mozilla Firefox (latest version)
Microsoft Edge (latest version)

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Junctions 10 Student Version (ARC+PIC+OSC)
£88Add to cart
Junctions 10 (ARC+PIC+OSC) for 1 User – 1yr Subscription
£1,425Add to cart

The cost excludes VAT

Discounts are available for upgrades, multiple licences, students and local authorities.  Please contact us to find out more

Junctions 10 Online Portal


Training Course Schedule

TRANSYT 16 Course (3-Day face-to-face)
22nd - 24th April 2024 at Crowthorne, Berkshire
£745Add to cart
Junctions 10 Course (2-Day, face-to-face)
19th - 20th March 2024 at Crowthorne, Berkshire
£720Add to cart
Junctions 10 Course (2-Day, online)
15th - 16th May 2024 at Online (UK time zone)
£720Add to cart

The cost is per delegate and excludes VAT

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