computer science

Sidra Intersection

Sidra Intersection is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Sidra Intersection rather than just read about it. In short: Sidra Intersection (styled SIDRA, previously called Sidra and aaSidra) is a software package used for intersection (junction), interchange and network capacity, level of service, performance and traffic impact analysis, and signalised intersection, interchange and network timing calculations by traffic design, operations and planning professionals. History First released in 1984, it has been under continuous develop…

Key takeaways

Sidra Intersection belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Sidra Intersection to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Sidra Intersection from memory before moving on to harder problems.

Reference excerpt

Sidra Intersection (styled SIDRA, previously called Sidra and aaSidra) is a software package used for intersection (junction), interchange and network capacity, level of service, performance and traffic impact analysis, and signalised intersection, interchange and network timing calculations by traffic design, operations and planning professionals.

History First released in 1984, it has been under continuous development in response to user feedback. Version 6.0 released in April 2013 added network modelling capability and new vehicle movement classes. Version 7.0 released in April 2016 included new timing analysis methods for Common Control Groups (multiple intersections operating under one signal controller) and Network Cycle Time and Signal Offset calculations for signal coordination. Version 9.0 released in May 2020 included improved network model processing efficiency and workflow efficiency through substantial user interface enhancements and model improvements. Version 9.1 introduced important traffic model enhancements and extensive user interface and model output improvements including network layout and roundabout layout enhancements, and customised reports and displays. The model enhancements include output by Movement Class, a new Variable Demand model, upstream delay and stop rate model for approach short lanes, the HCM Edition 6/7 Extended Roundabout Capacity Model and a combined pedestrian actuation and minor phase actuation method for signal timing calculations. Version 10 introduced significant updates and enhancements, including a new future-proof, versionless project file format (.sipx) designed for compatibility, reduced file sizes, and faster processing. It also features efficient volume data management through the new Volume Store, eliminating duplication of Sites and Networks for more streamlined Scenario Analysis. SIDRA MAPS integrates OpenStreetMap (OSM) data for advanced visualisation and site creation directly from map data. The software expands modelling capabilities with new Site Types—Turbo Roundabouts, Arterial Segments, Freeway Segments, and Freeway Segments with Ramps—and enhances signal timing analysis with real-number timings, multiple green periods, and improved performance models. Additional model enhancements include refined queue modelling and a new Exit Merge Queue Model. User interface improvements provide a redesigned ribbon, drag-and-drop functionality, and advanced search and import tools for easier navigation. Additionally, the updated VOLUMES Excel Utility allows seamless integration and processing of volume-related data directly within Excel. SIDRA INTERSECTION 11 was released in March 2026. It introduced major new features and various improvements. These include SIDRA ASSIGN (new traffic assignment module), use of Origin-Destination (O-D) Matrix Data for ASSIGN, SIDRA Glossary update including traffic assignment terms, enhanced Network Convergence method including a new Two-Loop Convergence process, improved User Interface for User Report Template dialogs, website changes including the implementation of new DOCS formatting, various model parameter updates, improvements to platoon modelling and proportion queued for oversaturated cases for multiple green periods, and user interface improvements. New Software Licensing including Personal and Team Subscription Licence products has been introduced. Sidra Intersection is a micro-analytical traffic evaluation tool that employs lane-by-lane and vehicle drive cycle models. It can be used to compare alternative treatments of individual intersections and networks of intersections involving signalised intersections (fixed-time/pretimed and actuated), roundabouts (not signalised), roundabouts with metering signals, fully signalised roundabouts, two-way stop and give-way (yield) sign control, all-way (4-way and 3-way) stop sign control, merging, single-point urban interchanges, traditional diamond and diverging diamond interchanges, basic freeway segments, signalised and unsignalised (zebra) midblock crossings for pedestrians, merging analysis and network modelling of these intersection and interchange types. Sidra Intersection allows modelling of separate Movement Classes (Light Vehicles, Heavy Vehicles, Buses, Bicycles, Large Trucks, Light Rail/Trams and six User Classes) with different vehicle characteristics. These movements can be allocated to different lanes, lane segments and signal phases; for example for modelling bus priority lanes and signals. In Australia and New Zealand, Sidra Intersection is endorsed by Austroads. In the US, Sidra Intersection is recognised by the US Highway Capacity Manual, TRB/FHWA 2010 Roundabout Guide (NCHRP Report 672) and various roundabout guides.

Lane-based intersection and network analysis method The lane-by-lane capacity and performance analysis method used by Sidra Intersection includes identifying any de facto exclusive lanes, unequal lane utilisation, lane change, modelling of short lanes (turn bays, lanes with parking upstream, and loss of a lane at the exit side) including delays and stops experienced by drivers in the queue upstream of short lane entry, and lane blockage in shared lanes including lanes containing opposed (permitted) turns, slip (bypass) lane movements and turns on red. Intersections and networks can be modelled in detail using this method and signal timings can be determined accordingly with advantages over approach-based and lane group-based methods.

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Sidra Intersection

Start with the simplest possible case. Write down what Sidra Intersection claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Sidra Intersection before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Sidra Intersection ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Sidra Intersection

In research: Sidra Intersection appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Sidra Intersection in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Sidra Intersection is common in secondary-school and first-year university syllabi. It links to neighbouring topics Road traffic management, Transport software, so understanding it makes those chapters shorter.
In everyday life: Look for Sidra Intersection outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Sidra Intersection in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Sidra Intersection means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Sidra Intersection out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Sidra Intersection in simple terms?

Why does Sidra Intersection matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Sidra Intersection?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Sidra Intersection.