Disclaimer - my site. It’s very focused on quiet routes, so will generally prefer a hilly road if the alternative is a traffic-infested one. Europe/North America/AU+NZ only at present.
Really impressive site, thanks for sharing it! Bonus: I'm just used to sites not having data / support for Canada; this was a pleasant surprise.
UX observation: clicking to create a start and end was relatively intuitive, but it took a while to find "Close route" to reset it (and be able to click for start / end points once more).
How do you determine quiet-ness? Is it just by the grade of the road, or do you have some kind of data feed for quietitude?
E.g. in the UK, some A-roads can be very quiet despite being technically major, whereas some B-roads or even ungraded can be very busy, e.g. if they are used as shortcuts.
It's by historic traffic data where available, defaulting to road class if not. (Before I added the traffic data, it used to route over rough mountain tracks in the Highlands to avoid A roads...)
This is good. Guessing you're already ahead of me, but a feature that I find super useful in competitors is an elevation map of the route after I've selected it.