Contact-Tracing Apps Vs Traffic Management Apps
Contact-Tracing-Apps are now being used by many and manufactures are also making available their standards of encryption that are to be used (with Opt-In Consent options) for better integration.
Are contact-tracing apps 'similar' to traffic based apps? They do not really concern themselves with who is driving, rather that, there is 'build up of vehicles' in certain areas and 'since it is a place that your vehicle historically visited' it must be notified (as per your consent) any travel to that place 'likely' to experience 'traffic'.
These heat-mapping exercises help manage medical hot-spot activity, though, it's vital to understand the trade-offs between Digital Encryption Vs Tech-Enablement by reviewing the actual 'mechanics of encryption' that ultimately enable these medical insights.
The IET Digital Library has many resources on the concepts of Encryption available and can be found here