SIDRA API UPDATED IN 11.0.4
New in SIDRA INTERSECTION 11.0.4
From 11.0.4, the SIDRA API can read and write SIDRA ASSIGN data: zones, O-D trip matrices, assignment settings and results. Write the O-D trip matrix for your study area, taken from your strategic model, into SIDRA ASSIGN, process the Assign Network, and bring travel time, delay, cost, fuel and emissions for every O-D pair back into your own reports.
SIDRA ASSIGN in the APIGet Started11.0.4 Release Notes
What 11.0.4 Adds
What Your Program Can Do in SIDRA ASSIGN
SIDRA ASSIGN is the lane-based traffic assignment feature of SIDRA INTERSECTION 11. From 11.0.4, the SIDRA API covers each step of an assignment, from the demand to the results. A program can:
| 1. Build the demand | Create Assign Volume Bins, zones and O-D volume sets, and write trip volumes for each Movement Class, with growth rates. |
| 2. Make an Assign Network | Create it from an existing Basic Network, link it to an Assign Volume Bin, and connect each zone to a leg. |
| 3. Set up the assignment | Choose All-or-Nothing, Incremental, User Equilibrium or Stochastic User Equilibrium. Set iterations, tolerances and Assign Scenarios, and Fixed Route shares for each route and Movement Class. |
| 4. Process and read the results | For each O-D pair, overall and by Movement Class: flow, degree of saturation, travel time, delay, stop rate, distance, speed, operating cost, fuel and emissions. Also the reported routes, the flow on each, the Sites along each route, and the convergence history. |
| Record the source | Give your program a name, and the API records it on every Site, Network, Site Volume Bin and Assign Volume Bin the program creates or changes. The Site and Network Properties dialogs show it. |
Why Use It
What It Means for Your SIDRA ASSIGN Work
Six uses that 11.0.4 opens up for engineers who already work in SIDRA ASSIGN.
Load O-D matrices from your strategic model
Your program reads the O-D output of your strategic model for the area you model in detail and writes it into an Assign Volume Bin, by Movement Class, instead of copying and pasting each matrix into SIDRA INTERSECTION. An Assign Network takes up to 50 zones.
Run every design year and tabulate O-D results
Add an O-D volume set and an Assign Scenario for each design year or growth assumption, run each scenario in turn, and write travel time, delay and cost for every O-D pair into one table.
Check convergence before you rely on a result
After each run, read the duality gap and the last steps of the convergence history, and list any run outside your tolerance before the results go into a report.
Report cost, fuel and emissions for every O-D pair
Read operating cost, fuel and emissions for each O-D pair and Movement Class, so an option can be compared on trip cost and emissions as well as travel time.
Compare modelled routes with your survey data
Read the reported routes between each O-D pair, the flow and travel time on each, and the Sites along each route, and set them beside observed travel times.
Show which program built a model
The source stamp is stored on every Site, Network and Volume Bin your program creates or changes, so a reviewer can see in the Site and Network Properties dialogs which program built a model.
Start Here
Two SIDRA ASSIGN Sample Programs
The 11.0.4 sample programs add two SIDRA ASSIGN examples, each in C#, C++ and Python:
| Built from code | Creates two roundabouts, a Basic Network, an Assign Volume Bin with four zones, and an Assign Network. It processes the network and prints the duality gap (a measure of convergence) and the flow on each route for one O-D pair. |
| Added to a supplied project | Opens a supplied project, adds three O-D volume sets and a second Assign Scenario, sets the assignment method, runs each scenario and writes the O-D, route and convergence results to CSV files. |
On api.sidrasolutions.com, the SIDRA ASSIGN page sets out the objects and the steps in order, and shows how the API names match the SIDRA ASSIGN User Guide. You need SIDRA INTERSECTION 11.0.4 or later.
Programs written for 11.0.3 also run on 11.0.4, with one change to check in existing scripts. The release notes list it, along with every addition.
SIDRA ASSIGN in the APISample Project GuideAbout SIDRA ASSIGN
Across SIDRA INTERSECTION 11
What the SIDRA API Does
The SIDRA API is the programming interface to SIDRA INTERSECTION. Beyond SIDRA ASSIGN, a program you write opens a project, works with its Sites and Networks, processes them and reads the results. That takes the repetition out of modelling work: entering volumes, processing one Site after another, copying results into a table.
| Open, create and save projects | Work with existing SIDRA INTERSECTION 11 project files, or create new ones. |
| Build Sites and Networks | Legs, lanes, phasing and volumes, written from your data instead of entered by hand. |
| Change inputs and scenarios | Volumes, Volume Bins and Scenarios, model settings, and Design Life and Flow Scale analysis. |
| Process Sites and Networks | One at a time, or every Site and Network in a project. |
| Read the results | Capacity, degree of saturation, level of service, delay, queue length, stop rate, travel time, fuel consumption, emissions and operating cost, for the Site and for its legs, lanes and movements. |
| Check the diagnostics | Processing warnings and diagnostic messages for every Site. |
api = SIAPI() api.OpenProject(r"C:\Samples\Demo.sipx") site = api.Project.SiteFolders[0].Sites[0] site.Process() print(site.Outputset.OutputSiteVehicle.Level_of_service)
Python. Open a project, process a Site, read a result. The core is five lines; set-up for each language is in Getting started.
Everyday Uses
- Update the volumes, process every Site, fill the results table. Read turning movement volumes from a spreadsheet or text file, write them into every Site, process, and write the movement and lane results back out.
- Process a whole intersection inventory in one run. Gather Sites from many project files into one, process them all, and rank them by degree of saturation, level of service or queue length.
- Run every volume scenario in one pass. Step through each scenario on a Site or Network, process it, read the results, and write one summary table across all of them.
- Compare design years and growth assumptions. Drive Design Life and Flow Scale analysis from a list of design years or growth factors.
- Check submitted models against your standard. Read the model settings and processing warnings of every Site in a project, and list what differs from your reference model.
- Report emissions and running cost, not only delay. Read CO2, NOx, CO, hydrocarbons, fuel and operating cost for each option.
- Check that network models settled. Report across a whole project which Network runs converged and which did not.
- Put SIDRA INTERSECTION inside your modelling chain. Read signal timings out for another tool, or write network data in from one.
The API reads and writes SIDRA INTERSECTION project files. Data from other tools reaches a project through your program, which reads the file and writes the values in.
Getting Connected
Languages and Set-Up
Use the language that suits your work. The sample programs run the same examples, including both SIDRA ASSIGN examples, in C#, C++ and Python.
| C# and VB.NET | Reference LB_SI11API.dll, the Version 11 late-binding wrapper, from the Downloads page of the API site. It keeps your program working with updates to Version 11. |
| C++ | Through the COM type library registered by the SIDRA INTERSECTION installer. |
| Python | Through Python.NET (the pythonnet package), with 64-bit Python. |
| VBA | Through COM, as for C++, with 64-bit Microsoft Office. The VOLUMES Excel utility in SIDRA UTILITIES is a worked example. |
What You Need
| Software | SIDRA INTERSECTION 11, installed and licensed on the same computer. Use 11.0.4 or later for SIDRA ASSIGN data. |
| Platform | Windows 10 or Windows 11, 64-bit only. Your program must run as a 64-bit process. |
| Runtime | The .NET 8 runtime, supplied by the SIDRA INTERSECTION installer. |
| Project files | SIDRA INTERSECTION 11 projects (.sipx), or new ones your program creates. Close a project in SIDRA INTERSECTION before your program opens it. |
Moving a Python script from Version 9.1 or 10? Version 11 connects through Python.NET, which replaces the earlier route. The API is updated for each major version of SIDRA INTERSECTION, so programs written for Version 11 will need updating for Version 12.
api.sidrasolutions.com
Documentation and Samples
The developer documentation has its own website. It is versioned: from 11.0.3, each release has its own copy, and the version selector lets you pick the one for your installation.
- SIDRA ASSIGN: new in 11.0.4. The objects, the steps in order, and how the API names match the SIDRA ASSIGN User Guide.
- Getting started: what to install, how to add the API in each language, and a first program.
- Object model: how a project's Sites, Networks, legs and lanes fit together.
- Code samples: short walkthroughs, and downloadable sample projects in C#, C++ and Python.
- API reference: every interface, property and method, by release.
- For AI agents: a page and machine-readable indexes, so AI coding assistants work from the published reference.
- Previous versions: Help, wrapper files and sample projects for SIDRA INTERSECTION 10 and 9.1.
Licensing
Included With Your Licence
The API is included with your SIDRA INTERSECTION licence at no extra charge. SIDRA ASSIGN is part of SIDRA INTERSECTION 11, so the new SIDRA ASSIGN features come with it.
- A program that uses the API runs on a computer with SIDRA INTERSECTION installed and licensed. Each end user of the program needs a licensed copy, including where the link is provided in another vendor's product.
- The 14-day evaluation licence includes the API. It is for evaluation, research, testing and training, not for commercial, client or income-generating work.
- Operational use, such as in a traffic management centre or a traffic signal control system, may need a Special Application Licence. Contact us to check.
- The full terms are in the SIDRA API section of our Terms of Use.
Questions or feedback about the API? Contact technical support. For licence types, see Licensing.
SIDRA API · Updated in 11.0.4
Bring SIDRA ASSIGN Into Your Own Tools
Update to SIDRA INTERSECTION 11.0.4, read the SIDRA ASSIGN page on the API site, and run the two SIDRA ASSIGN sample programs. Then adapt their code to write your own O-D matrices.