Are you interested in modeling with UML Real-Time? Good news: Design Room ONE latest delivery, version 2018.44 has been added a new easy-to-deploy TrafficLight sample.
It contains analysis model describing the use case. As well as the detailed design model specifying capsules, their structure, behavior and communication protocols.
If you want to play with the source model it is available from GitHub project. And check the updated Installation Instructions to extend RSA RTE or RealTime Software Tooling (RTist) with a plugin to export your Real-Time models to Design Room ONE.