This is not about the risk of getting infected on the skintrack or the trail. It’s about the parking lot at the trailhead, the gas stations and bathrooms en route, the grocery stores in town. It’s about the risk to and drain on emergency and medical resources if you become sick or injured – not just the risk of exposure, but also the scarce personal protective equipment used while treating you.
Based on the numbers of aggressive cyclists out on Seattle's trails and roads, I'd say there's at least one more (Strava) service that should follow suit.
What do you think?