Understanding fundamental concepts and principles for effective intersection and network modelling

A good understanding of traffic operations is essential for effective use of traffic models for intersection and network design, performance assessment and transport planning purposes. Model calibration is an important element of this process. SIDRA Training is not just about intersection and network analysis, but aims to improve general understanding of operational analysis of all traffic facilities.

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Upcoming Events

We have scheduled the following events for January 2021:

Target Audience

The SIDRA MODEL FUNDAMENTALS training program is offered for SIDRA users with all levels of experience. It will be of benefit to traffic and transport professionals and students interested in the essential concepts of traffic modelling and principles of traffic analysis.


This training will focus on traffic variables, concepts and principles that need to be understood for effective intersection and network modelling from a practical perspective using an analytical software tool such as SIDRA INTERSECTION. These traffic variables are of importance in preparing input, interpreting output, and calibrating the model for best representation of real-life traffic conditions.

The knowledge gained at this online training will be useful generally in the use of all traffic and transport modelling software tools.

Traffic-Rule and Units

Metric units will be used during this training. Various displays used in the presentations will be for Left-Hand Traffic Rule. This is not critical to the learning of the material presented.


This training program will be presented by Rahmi Akçelik, Mark Besley, David Nash and Ian Espada.

Technical Requirements

Please read these important Technical Requirements for our training programs.

    Recommendations for Viewing

    You will need to view two windows at the same time, one window to view the Presenter's desktop and another window to view the Training Book for exercises.

    Program Contents

    The SIDRA MODEL FUNDAMENTALS online training program (View PDF) consists of 3 Modules:

    Module A

    Topic A1: Traffic Models - An Introduction

    Model Benefits / Objectives, Model Consistency, Decisions based on traffic modelling, Movement Classes. Analytical and Microsimulation Models, Model Categories, Model Types, Model Level of Detail, Lane-Based Modelling, Understanding Traffic Models.

    Topic A2: Fundamentals of Traffic Flow
    Uninterrupted and Interrupted Flows, Three Key Parameters, Headway - Spacing - Speed relationship.

    Exercise A2: Speed, Spacing, Headway, Density, Flow Rate

    Topic A3: Uninterrupted Flows
    Definition, Spacing - Speed - Flow, Other Fundamental Relationships, Speed-Flow Models for Uninterrupted Traffic Facilities. Spot Speed, Travel Speed and Travel Time. Bunched Headway Model, Proportion Bunched for Uninterrupted Flows, Extra Bunching for Upstream Signal Effects. Arrival Headway Distributions.

    Exercise A3: Proportion Bunched and Extra Bunching

    Topic A4: Interrupted Flows
    Definition, Conflict points at intersections. Choice of intersection type: Signals vs Roundabouts. Alternative intersections and interchanges, SIDRA INTERSECTION Network Templates.

    Topic A5: Capacity, Degree of Saturation
    Demand Flows, Capacity, Degree of Saturation, Practical Capacity

    Exercise A5: Saturation Flow Rate and Degree of Saturation

    Topic A6: Lane Flows and Unequal Lane Use
    Causes of Unequal Lane Use at Intersections. Unequal Lane Use at Closely-Spaced Intersections. Unequal Lane Use Example. Lane Utilisation and Approach Capacity (Effective). Defacto Exclusive Lanes.

    Exercise A6: Lane Utilisation Ratio and Approach Capacity (Effective)

    Q & A

    Module B

    Topic B1: Saturation Flow
    Saturation Flow Rate and Speed, Queue Discharge Surveys. Saturation Headway Model. Saturation Flow, Start Loss, End Gain. Displayed and Effective Green Times. Saturation Flow Survey, SCATS MF. Short Lane Saturation Flow, Short Lane Queue.

    Exercise B1: Saturation Headway and Saturation Flow Rate

    Topic B2: Saturation Flow Estimation
    Saturation Flow Estimation in veh/h, Movement Class and Turning Vehicle Effects. Flow Rate and Saturation Flow Rate in veh/h and tcu/h. Shared Lane Saturation Flow Rate.

    Exercise B2: Shared Lane Saturation Flow Rate

    Topic B3: Traffic Signal Timing
    Signal Timing Analysis Methods (EQUISAT /SCATS and Actuated). Signal Phasing, Variable Phase Sequence Analysis. Common Control Groups. Critical Movement Diagram.

    Exercise B3: Critical Movement Diagram

    Topic B4: Pedestrians
    Pedestrian Crossing Types (Signalised Intersections, Midblock Crossings). Pedestrians at Signals, Pedestrian Protection. Pedestrian Crossing Distances and Speeds, Pedestrian Minimum Time, Pedestrian Timing Parameters. Pedestrian Actuation. Unsignalised Pedestrian Crossing Analysis.

    Exercise B4: Pedestrian Minimum Time

    Topic B5: Traffic Signal Coordination
    Signal Platoon Patterns, Platoon Ratio, Arrival Type. Platoon Dispersion Model. Offset Definition, Relative Offset, Stopline Travel Time. Time-Distance Diagram.

    Exercise B5: Platoon Ratio and Arrival Type

    Q & A

    Module C

    Topic C1: Roundabouts
    Roundabout Capacity Models, Unequal lane use cases as observed at UK Roundabouts. SIDRA Roundabout Capacity Model. Capacity model with roundabout approach interactions. Follow-up Headway and Critical Gap, A useful rule of thumb for gap acceptance parameters, Other Features of SIDRA Roundabout Model, Bunched Headway Model, Geometry parameters. Capacity Constraint, Unbalanced Flows, Roundabout Metering Signals.

    Exercise C1: Circulating Flow Rate with Capacity Constraint

    Topic C2: Sign Control
    Gap Acceptance Model (Driver Behaviour Focus), Gap Acceptance Parameters (Base values and Adjustments), Movement Class Effects, Opposing Flow Effects. Gap Acceptance Model by Signal Analogy. Gap Acceptance Survey Method.

    Exercise C2: Critical Gap and Follow-Up Headway Adjustment

    Topic C3: Intersection Performance and Level of Service
    Delay definitions, Queue definitions. SIDRA Performance Estimates, Overflow Concept, Fundamental Diagram of Intersection Performance. Level of Service. Vehicle Path Model, Acceleration - Deceleration Models. Fuel Consumption and Emissions, Operating Cost.

    Exercise C3: Level of Service

    Topic C4: Model Calibration
    Local Conditions and Model Calibration. Key Model Calibration Parameters.
    Signal Saturation Flow Example. SIDRA Lane-based INTERSECTION and NETWORK model (iterative method), Iterative Methods for Intersection and Network Modelling.

    Exercise C4: Saturation Flow Calibration

    Topic C5: Network Modelling
    Lane Blockage and Capacity Constraint, Capacity Reduction due to Lane Blockage. SIDRA NETWORK Model. Signalised Diamond Interchange (SDI), Diverging Diamond Interchange (DDI), Continuous Flow Intersection (CFI). Lane Movement Flow Proportions.
    Midblock Lane Changes.

    Exercise C5: Capacity Reduction due to Lane Blockage

    Q & A

    Choosing your Modules

    Attending all three Modules is recommended.

    Separate Registration for each Module

    Separate registration is required for each Module. For instance, if you would like to attend both Module A and Module B, you are required to register for each of these two Modules separately.

    Pricing (per Module)

    Click here to view Pricing and read important information regarding payment.

    Webex Invitation

    We will send you an email invitation via Webex approximately 48 hours prior to the event.

    Other Details

    Completion of Training

    At the end of your Module, we will ask you to complete and submit a Training Evaluation Survey so we can get feedback on your experience. The information and feedback you provide is valuable for us in designing and improving our programs.

    After completion of training, we will send you a Confirmation of Attendance. We will also send you links for downloading your Answers to Exercises Books.


    Please read these important Conditions for attending our training programs.


    Email: The best way to contact us is via this form.
    Phone: +61 3 9830 7123 - Monday to Friday 9.00 am to 5.00 pm - AEDT

    Registrations Open - Jan 2021 Online Training. View Upcoming Events..