An old, previously unreleased Java + Swing project circa Summer '13. Now on GitHub! Unfinished, but demoable.

TrafficSim

What if cars had wireless sensors communicating their movements to city-wide traffic networks? Or every intersection had cameras able to count the incoming waves?

This simulation demos a traffic grid system where lights can switch intelligently to minimise disruptions.

Its current form is simple: it assumes cars drive shortest path routes to their destination, and it calculates simulation data while rendering in real time. It loads OpenStreetMap data to construct a network of roads, and randomly spawns a wave of cars driving unique routes. Some simplifications regarding traffic laws are made, too.

Future work could be to:

• Fully decouple simulation from rendering
• Implement some sort of monitoring with feedback metrics
• Allow customisation for traffic in-/out-flows (i.e. vehicle sources/sinks)
• Add traffic controllers (lights) with improved performance
• Improve reality of simulation (traffic laws, physics)
• Fix outstanding issues and add some tests

Build

Install bazelisk

# For example, if you have node setup already
npm i -g @bazel/bazelisk

Then

# "//..." means build all
bazel build //...

Run

Run the main TrafficSim program with:

./bazel-bin/src/main/java/trafficsim/TrafficSim

Development

Bazel

Miscellaneous bazel commands

bazel build //...
bazel test //...
bazel run //:buildifier # Lint/fix bazel files
bazel clean  # Use sparingly

To regenerate BUILD.bazel files using gazelle:

bazel run //:gazelle

To regenerate build files, build and then run in one command:

./build-run.sh

Basing build on new image

To set a new open container image in MODULE.bazel, replace image and digest in oci.pull(...).

You can get the list of supported images from: https://github.com/GoogleContainerTools/distroless

Then use cosign to checksum the image before building with it:

go install github.com/sigstore/cosign/v2/cmd/cosign@latest
cosign verify gcr.io/distroless/java11-debian11 --certificate-oidc-issuer https://accounts.google.com  --certificate-identity keyless@distroless.iam.gserviceaccount.com

ref: https://docs.sigstore.dev/system_config/installation/

Credits

Pathfinding uses code from the AI for Games library.