SIDRA API NOW ONLINE
Write the script once. Run every scenario.
Guides, working samples and the full API reference, at api.sidrasolutions.com
Another design year. Revised counts. One more option to test. The SIDRA API lets your own code open a project, change the inputs, process every Site and read the results. The repeat work runs itself. Your time goes on what the results mean.
Get started with the APIAPI Reference
Updating inputs, running scenarios and collecting results are essential parts of a traffic study. Repeating those steps by hand takes time you could spend comparing options and refining your design. The SIDRA Application Programming Interface (API) lets your code open projects, change inputs, run analyses and read results. It is included with SIDRA INTERSECTION 11 and works with your installed, licensed software.
Getting started is now easier. Launched on 11 September 2026, api.sidrasolutions.com brings the documentation previously supplied in a Help file onto the web. Practical guides, working code samples and troubleshooting advice give you or your developer a clear starting point for your first script.
When you need the detail, the complete API reference is there too, generated from the API for each documented release. Use the version selector to find the documentation for your version of SIDRA INTERSECTION.
Why Use It
Make Everyday Project Work Easier
Think about the steps you repeat on every project. Here are four ways your own scripts can help.
Run the scenarios your project needs
A client asks for another design year or a revised growth assumption. Use a script to update inputs and process a series of Sites or scenarios, without stepping through each one manually. Build a repeatable process for sensitivity testing and design comparisons, then reuse it when the brief changes.
Bring results straight into your reports
Still copying results into a spreadsheet for each option? Use the API to read the outputs you need and feed them into your own reporting tools. Build a reporting process around the tables, dashboards and templates your team already uses, and reuse it for the next set of results.
Turn your traffic data into model inputs
Your turning movement counts are already in a data file. Write code that reads those counts and creates or updates SIDRA models, reducing repeated data entry. When revised counts arrive, run the same process again and spend your time checking the model and assessing the changes.
Connect the tools your team relies on
Bring data preparation, SIDRA analysis and reporting together in a workflow you control. Whether you are extending an existing script or building an internal tool, the API lets you make SIDRA INTERSECTION part of the way your team works.
Getting Connected
Build With a Language You Know
Use C#, VB.NET, C++ or Python to connect your tools to SIDRA INTERSECTION. The documentation explains the setup, with complete working samples in C#, C++ and Python to help you get moving.
| C# and VB.NET | Connect directly using LB_SI11API.dll, the late-binding wrapper you download from the API site. |
| C++ | Connect through COM using the type library registered by the SIDRA INTERSECTION installer. |
| Python | Load the API directly with Python.NET, using the pythonnet package. |
Each sample opens a project, processes Sites and reads results. Start with a working example, then adapt it to a task that matters to your team.
What You Need to Get Started
| Licence | A licensed copy of SIDRA INTERSECTION 11 installed on the computer running the API. Each end user of an application that uses the API also needs a licensed copy. See the SIDRA API section of our Terms of Use. |
| Platform | Windows 10 or Windows 11, 64-bit only. |
| Runtime | The .NET 8 runtime, supplied by the SIDRA INTERSECTION installer. Your application must run as a 64-bit process. The getting started guide covers the setup for your language. |
| Project files | Use a SIDRA INTERSECTION 11 project in .sipx format, or create one through the API. |
Give Your AI Coding Assistant the SIDRA Details
If you use an AI assistant to help write scripts, give it the SIDRA API documentation as a starting point. The site includes llms.txt and llms-full.txt, plus individual API pages in Markdown. These provide the documented API types and methods your assistant needs when helping you turn a workflow idea into code.
Your First Script Can Be Small
Choose one task you find yourself repeating: updating traffic volumes, running a set of scenarios or collecting results for a comparison table. Follow the getting started guide to connect to SIDRA INTERSECTION and open a project, then use a code sample to run an analysis and read the results. Build from there, with a useful first task and a clear reason to script it.
SIDRA API Reference
Get More From SIDRA INTERSECTION
Turn a task you repeat into a process you can reuse. Explore what the SIDRA API can do, then follow the guides and working samples to build a script for your next project.