Version History

Aerial photograph of road

Brief Version History of SIDRA INTERSECTION

A brief version history (1975-2023) of SIDRA INTERSECTION development is given below.

Original version SIDRA 1 for signalised intersection analysis was developed by Dr Rahmi Akçelik during 1975-1979 (Akçelik 1979).

The word SIDRA was created as an acronym for Signalised Intersection Design and Research Aid. With the addition of analysis methods for roundabouts and unsignalised intersections in later versions, the acronym was stated as Signalised & unsignalised Intersection Design and Research Aid.

SIDRA 2.0 was released in August 1984 as a main-frame computer program for signalised intersection capacity and timing analysis based on the Australian Road Research Board (ARRB) Research Report ARR 123 (Akçelik 1981a, 1984). A major trial workshop tested a pre-release version of the software in May 1983. Version 2 was launched at a workshop held during the 12th ARRB Conference in Hobart. A micro-computer version for "any IBM-PC/XT or compatible computer that runs the MS-DOS operating system" was made available in December 1984.

SIDRA Version 2.1 was released in March 1985. It included minor programming improvements.

SIDRA Version 2.2 was released in February 1986 with more extensive improvements to the program.

In September 1986, the ARRB energy research team (Bowyer, Akçelik and Biggs) received the Institute of Transportation Engineers (USA) 1986 Transportation Energy Conservation Award in Memory of Frederick A. Wagner for research into energy savings from urban traffic management.

In July 1986, licences were issued to 40 organisations in 8 countries.

SIDRA Version 3.0 was released in July 1987. The program was still limited to signalised intersections. Version 3.0 included major changes to the program structure and input data preparation method, improvements to the traffic model and signal timing methods, and introduced of models to estimate fuel consumption, emissions and operating cost based on award-winning ARRB energy modelling work (Akçelik 1983, Bowyer, Akçelik and Biggs 1985).

SIDRA Version 3.1 was released in August 1988 primarily as a personal computer software package although the main-frame computer version was still supported. It included a menu-driven interface with the SIDMAN input data manager for the PC version, further improvements to the traffic model and signal timing methods, and an option to implement the US Highway Capacity Manual (1985) method for signalised intersections.

In November 1988, SIDRA was in use by 107 organisations in 16 countries.

SIDRA Version 3.2 was released in May 1990 as a new major version of the software. It included significant user interface, programming and traffic model improvements. A fully implemented US Highway Capacity Manual option, continuous and undetected movement types, delay progression factors for signal coordination effects as well as a partly developed roundabout and unsignalised intersection model were introduced in this version.

In May 1990, SIDRA was in use by 141 organisations in 23 countries.

SIDRA Version 4.0 was released in September 1991. This new version differed from earlier versions substantially. It introduced significant software changes including the graphic-based input data editor RIDES (replacing SIDMAN), other improvements to the user interface, help system and defaults files. Approach-based data, improved signal phasing data entry, pictures for checking input data visually, and a prototype output graphics facility (GOSID) were introduced. Methods to analyse roundabouts and other unsignalised intersections were available but qualified as "not fully developed yet". This version was available for personal computers only (DOS operating system).

SIDRA Version 4.05 released in April 1992 included improvements to the RIDES and GOSID modules, a new VIEWS module for text output display, and "substantial improvements with the new roundabout capacity method (new capacity equations implemented)".

SIDRA Version 4.07 was released in March 1993 as a major update. It incorporated major enhancements towards Version 4.1. The improvements included implementation of the roundabout analysis method described in AUSTROADS (1993) Roundabout Guide, as well as improvements to other aspects of modelling and user interface. In Version 4.07, the term "Victorian Rule" was changed to "New Zealand Rule" as the rule ceased to apply in the State of Victoria, Australia on 28 February 1993.

SIDRA Version 4.1 was released in September 1995 as a major new version. This was the last full DOS version of SIDRA. Various major enhancements were introduced in this version, particularly in many aspects of traffic modelling with the aim of providing complete and consistent modelling of capacity and traffic performance for different types of intersection. Results of new ARRB research on roundabout modelling (introducing the effect of origin-destination patterns in order to model unbalanced demand flows at roundabouts) and various methods described in the 1994 Highway Capacity Manual were incorporated into this version. Heavy vehicle modelling was improved significantly and geometric delay modeling was introduced for all types of intersection.

New Features introduced in SIDRA 4.1 and subsequent versions are listed in some detail in the following section.

An effectiveness audit of ARRB intersection capacity research, which is the basis of the SIDRA software package, was conducted during 1992-1993. The audit report (TAYLOR, et al. 1993) stated that "The (audit) panel rated the technical merit of the research as very high and concluded that it has established international professional reputations for the Board (ARRB) in the fields of traffic signals analysis, roundabout analysis, and energy and emissions modelling" and a survey of SIDRA users conducted by the audit panel indicated that "Users valued the theoretical basis of SIDRA, the consistency and validity of results that it produced, and the ability to test variations of a base data set.".

SIDRA was internationalised strongly during this period, especially with significant increases in organisations using SIDRA in the USA. Dr Rahmi Akçelik organised the US Transportation Research Board 2nd International Symposium on Highway Capacity which was held in Sydney during August 1994.

In June 1992, SIDRA was in use by 206 organisations in 36 countries, increased to 370 organisations in 40 countries in June 1994, and to over 520 organisations in more than 40 countries (with more than 100 organisations in the USA) in October 1995.

SIDRA Version 5.0 was released in June 1996. This was the first version of SIDRA to run under Windows 3.1 and Windows 95, with all file management, configuration, computation, and text output viewing functions in full Windows environment ("IBM compatible PC - 386 or better") but the graphic-based input and output modules RIDES and GOSID remaining in DOS. The new modelling features of Version 5 included a new progression factor for queue length and related performance measures, new actuated signal performance models, revised fixed-time signal performance models for compatibility with actuated signals, and timing method for actuated signals.

In July 1996, SIDRA was in use by over 600 organisations in more than 40 countries (including 150 organisations in the USA and Canada).

SIDRA Version 5.1 was released in January 1998. It included significant enhancements to roundabout and actuated signal analysis methods. A Windows style Graphs utility ws introduced.

In December 1998, SIDRA was in use by 1020 organisations in 61 countries.

SIDRA Version 5.2 was released in January 1999. This was last version developed under ARRB Transport Research Ltd. Major enhancements introduced in Version 5.2 included the 1997 Highway Capacity Manual (HCM 1997) method for level of service, delay and capacity, HCM 1997 gap acceptance parameters as general defaults (for all versions) for two-way stop and give-way / yield control, HCM 1997 and other alternative capacity models for roundabouts, and a sensitivity analysis facility.

In March 1999, Dr Rahmi Akçelik received the prestigious 1999 Clunies Ross National Science and Technology Award for outstanding commitment and contribution to the application of science and technology in Australia and for inspirational leadership of future scientist). The news release about the award stated "The Ian Clunies Ross Memorial Foundation summarised Dr Akçelik's contribution as “easing the frustrations of urban motoring through intelligent traffic intersection design”. Dr Akçelik’s work has provided an outstanding contribution to scientific knowledge and to the transfer of technology and application of science in Australia and the world. He has “gone the extra mile” in training and advising hundreds of Australian and international traffic systems professionals.".

In June 1999, SIDRA was in use by 1125 organisations in 66 countries.

Dr R. Akçelik left ARRB and established Akcelik & Associates Pty Ltd in July 1999.

Akcelik & Associates Pty Ltd acquired full ownership of SIDRA in February 2000. SIDRA Version 5.3 was released with the same features as SIDRA 5.2 except that copyright provisions to reflect the new ownership by Akcelik & Associates were implemented in the software, and more advanced methods of program compilation were used.

In June 2000, SIDRA was in use at 1240 sites in 69 countries.

Akcelik & Associates Pty Ltd renamed SIDRA as aaSIDRA©, short for "akcelik & associates SIDRA". aaSIDRA Version 1 was released as the first major new version by Akcelik & Associates in July 2000 (version renumbering applied) . A new front end (Windows shell) was introduced in this version as a 32-bit application for Windows 95/98/NT4/2000. Better file management was provided with direct access to individual text output tables and graphs, and access to the input and graphical output modules through a Project Tree structure.

In April 2002, SIDRA was in use at 1492 sites in 72 countries.

aaSIDRA Version 2.0 was released in May 2002. The new features of this version included graphical displays (intersection geometry, signal phasing and movement statistics) in Windows environment (replacing the output module GOSID), traffic model enhancements, and various input and output enhancements including HTML style text output.

aaSIDRA Version 2.1 was released in November 2004. This was a major version which introduced extensive improvements to traffic models, defaults systems and the user interface. Major refinements were introduced to roundabout capacity and performance models. New default values of gap acceptance parameters were introduced for all defaults systems except the US HCM versions.

In October 2004, SIDRA was in use at 1824 sites in 80 countries, increasing to 2157 sites in 86 countries in July 2006.

In 2006, Akcelik & Associates Pty Ltd introduced SIDRA SOLUTIONS© as the brand name for its software products. The product name SIDRA INTERSECTION was introduced to replace aaSIDRA.

SIDRA INTERSECTION Version 3.0 was released in August 2006 as the first version in full Windows environment. SIDRA INTERSECTION version 3.0 was a major step in the development of SIDRA software. This new-generation SIDRA INTERSECTION software was based on the Microsoft .NET Framework version 2, with all input and output in full Windows environment. There had been significant restructuring of input data, the defaults system, file management, configuration and other program facilities.

SIDRA INTERSECTION Version 3.1 was released in December 2006. A number of enhancements were added and various problems found with version 3.0 were resolved.

SIDRA INTERSECTION Version 3.2 was released in July 2007. The changes introduced in this version included several new features, enhancements to various features, and resolving of some problems discovered subsequent to the release of SIDRA 3.1.

Akcelik & Associates was the COMMENDEE in the Small Business Awards category in 2008 Governor of Victoria Export Awards.

In June 2008, SIDRA was in use at 2460 sites in 89 countries, increasing to 2610 sites in 92 countries in June 2009.

SIDRA INTERSECTION Version 4.0 was released in July 2009 with major enhancements to user interface, general program features and traffic modelling capabilities. These included a new user interface with enhanced input dialogs, output reports and displays in Microsoft Office 2007 style (tabs and ribbon), significant improvements to file management, input dialogs and error handling, API (Application Programming Interface) for users to interface other programs to SIDRA INTERSECTION with full access to input and output data, and a new licensing system. New input and output data structures were developed to enable the API facility.

The format of SIDRA INTERSECTION Version 4.0 Project files (extension sip) differed from the format used by previous Versions 3 files (extension aap).

A new website and eCommerce system were introduced to coincide with the release of Version 4.

Akcelik & Associates was the WINNER of the Small Business Awards in 2009 Governor of Victoria Export Awards, and a finalist of 2009 TELSTRA Small Business Award.

In May 2010, SIDRA INTERSECTION was in use by 1070 organisations in 66 countries (a new user count system was introduced with the release of new licensing system with this version, excluding users of old versions of the software).

SIDRA INTERSECTION Version 5.0 was released in July 2010 with modified Project file management and program control, enhancements to the user interface including a more intuitive intersection geometry configuration method, improved roundabout and other intersection layout pictures, various model improvements including timing method for roundabout metering analysis, important new templates, a number of SIDRA UTILITIES (incorporating API applications) such as OUTPUT COMPARISON and VARIABLE RUN programs and VOLUMES Excel application, and a much extended API method to enable access to most input and output data.

Akcelik & Associates won the 2010 TELSTRA Business Awards – Victorian Innovation Award.

In February 2011, SIDRA INTERSECTION was in use by 1205 organisations in 67 countries.

SIDRA INTERSECTION Version 5.1 was released in March 2011, coinciding with the release of HCM 2010. It included full integration of the HCM 2010 roundabout capacity model, and HCM 2010 level of service methods, parameter defaults and delay models were adopted. This version included extensive enhancements to user interface, program features and traffic models.

In an update released in April 2012, the "New Zealand Rule" was set to "No" by default in the New Zealand model as the rule ceased to apply in New Zealand on 25 March 2012.

In March 2013, SIDRA INTERSECTION was in use by 1430 organisations in 75 countries.

SIDRA INTERSECTION Version 6.0 was released in April 2013. It introduced the biggest changes in the 30-year history of the software. Three major elements of change were network modelling capability, movement classes, and data and modelling by Origin-Destination movements. Major data structure and user interface changes were implemented as a result.

Major enhancements were introduced through software updates after the initial release.

Akcelik & Associates was a finalist in the Small Business category of the 2014 Telstra Business Awards.

In December 2014, Dr Rahmi Akçelik received the 2014 Roads Australia Award for Technical Excellence in recognition of the exceptional achievement of an individual in a technical or scientific area relevant to transport. Roads Australia is a non-political industry association that acts as the national peak body of Australian road transport stakeholders. It represents the International Road Federation (IRF) in Australia and is represented on the World Executive Board of the IRF. The selection criteria for the award included the Field of Contribution ("The field of contribution must be in a technical or scientific area relevant to transport.") and Impact of Contribution ("The contribution must be outstanding. This will be measured directly in terms of its impact on the industry, the advancement of science and the community.").

In January 2015, SIDRA INTERSECTION was in use by 1760 organisations in 84 countries.

SIDRA INTERSECTION 6.1 was released in February 2015. A major improvement in this version was modelling of signal coordination effects using Signal Offsets and second-by-second platoon patterns including lane changes and platoon dispersion.

SIDRA INTERSECTION 7.0 was released in April 2016. Major improvements in this version were introduction of a new timing analysis method for Common Control Groups (multiple intersections operating under one signal controller), introduction of Network Cycle Time and Signal Offset calculations, and introduction of Routes for performance reports and displays, and for signal Offset calculations. Significant user interface improvements were introduced including many new output reports and displays.

SIDRA INTERSECTION 8.0 was released in April 2018. This version offers much improved network model processing efficiency and improved workflow efficiency through substantial user interface enhancements as well as important model improvements. These include increased computing speeds for the iterative network analysis method, optimum cycle time for networks and common control groups, network demand and sensitivity analysis methods, graphical displays of intersection geometry, volumes, signal phasing and movement IDs in Site input dialogs allowing direct data entry, a large number of new reports and displays for Sites, Networks and Routes including Project Summary and the User Report facility based on user-defined report templates.

SIDRA INTERSECTION 9.0 was released in May 2020. This version introduces important general software changes, some much wanted traffic model features and extensive user interface enhancements. These include increased Network size (up to 50 Sites); Map Extract tool; new tab, ribbon and project pane structure; PDF Output; Layout picture improvements including variable size and elliptical shapes for roundabouts; slip lane and midblock unsignalised pedestrian crossings; models for exit short lane merge and U-turn before intersection; graphical Interactive Offsets function; Multiple Phase Sequence analysis; new Manage tab for enhanced user settings; Queue Analysis, Pedestrian Analysis and Fuel, Emissions & Cost reports; consistent Approach, Lane, Movement, Lane Flows and Movement Flows displays for Sites, Networks and Routes; and Network Templates for modelling staged crossings, paired intersections, interchanges and innovative intersection and interchange designs.

SIDRA INTERSECTION 9.1 was released in November 2022. This version introduces important traffic model enhancements and extensive user interface and model output improvements. These include output reports and displays by Movement Class, Pedestrians and Persons; a new Variable Demand model using the Initial Queued Demand parameter; updated congestion term in performance functions; a new upstream delay and stop rate model for approach short lanes; the HCM Edition 6 Extended Roundabout Capacity Model and new US format phase labelling (mainly for US users); a combined Pedestrian Actuation and Minor Phase Actuation method for signal timing calculations; improved multi-sequence signal phasing and timing analysis; a new function to import signal sequences; Time-Distance displays with secondary platoons and a new displayed signal timings option; Extra Midblock Delay parameter; new and improved Network and Site Templates; improved Roundabout Layout and Network Layout pictures; new Network Configuration features; and an updated VOLUMES Excel application with new function to Import Volumes from external sources. Several new input parameters have been added without requiring any change to the project file format (sip9 extension).

Register now for our new 2023 SIDRA Training Programs! Upcoming Events..