Traffic modelling and network assessment

SIDRA intersection capacity analysis

The data-driven case that convinces council your intersection will actually perform.

SIDRA Intersection is the industry-standard analytical software for detailed, lane-by-lane modelling of traffic flow at intersections, roundabouts, and signalised networks — mandated by most Australian road authorities, including TfNSW, for development applications affecting intersection performance.

What SIDRA measures

MetricWhat it means / benchmark
Level of Service (LoS)An A–F grade for how well an intersection is operating — A is free-flowing, F is gridlock. Benchmark: LoS D or better in peak periods.
Degree of Saturation (v/c ratio)How close the intersection is to its capacity limit. Benchmark: below 0.90.
Average DelayAverage time a vehicle is stopped or slowed at the intersection. Assessed against LoS.
95th Percentile QueueThe practical maximum queue length, in metres, not exceeded 95% of the time. Must not block driveways or upstream intersections.

Process

  1. 01

    Data collection — traffic counts across weekday AM and PM peaks, site geometry, and signal phasing from the relevant authority

  2. 02

    Model build & calibration — calibrated against observed on-site conditions

  3. 03

    Scenario testing — a “do nothing” case compared against a “do something” case across opening year and future design horizon

PROC 01—04

How the engagement moves

From enquiry to controlled issue
  1. Step 01Send the project

    Provide the site, available drawings and the issue that needs resolving.

  2. Step 02Confirm the scope

    We identify the required assessment, documentation, programme and fee.

  3. Step 03Assess and coordinate

    The technical work is developed against the project and authority requirements.

  4. Step 04Check and issue

    The agreed review is completed before controlled issue and support through comments.

FAQ

Common questions

Is SIDRA analysis required for every development application?

No — it depends on project scale and anticipated traffic generation, as determined by the relevant council or road authority.

How does SIDRA differ from simulation software?

SIDRA suits detailed, lane-by-lane analysis of individual intersections. Simulation platforms model vehicle-by-vehicle behaviour across larger networks — better suited to queue spillback or multi-intersection interactions.

Does SIDRA account for pedestrians and cyclists?

Yes — delay, Level of Service, and crossing time outputs are produced for pedestrians and cyclists as well as vehicles.

What happens if the analysis shows LoS E or F?

It indicates mitigation is required — signal phasing changes, lane reconfiguration, or a physical upgrade — which are modelled to demonstrate a credible path to an acceptable Level of Service.

Traffic modelling and network assessment

Send us the drawings. We'll tell you what you need.

Request a fee proposal

Send us the drawings. We'll tell you what you need — a written scope and fixed fee come back to you.

Attach plans

Your details and files are used only to scope and respond to this enquiry. We don't add you to a mailing list or share your information.


Capability statement

Tell us where to send it and the capability statement comes to your inbox — services, standards, the register of people, and how an engagement runs.

What to send
1. Site address
2. Plans, if they exist
3. A description of the works
Sightline Traffic EngineersContact
1800 008 782
plans@sightlinetraffic.com.au
Suite 413, 388 George St, Sydney NSW 2000
Mon–Fri, 8am–5pm
ABN 16 699 960 668