We get most of the data for our maps from OpenStreetMap.org, a phenomenal project to collect and aggregate map information for the globe. All of that data is copyright OpenStreetMap.org contributors, under CC-BY-SA 2.0. You can read more about their licensing here. Here is the crux of our interpretation:
We like sharing a lot, so we're more than happy for you to use the ratings and comments about roads in other applications or context. Just be nice about it - give attribution to the user and SweetOpenRoads.com and don't scrape the data (obey robots.txt). If you would like the aggregate data all packaged up for you, get in touch with us at email@example.com and we can work something out. We haven't put together reliable systems for this yet out of timecrunch, not out of dislike of sharing.
Note that we're still very young and feeling out the best way to approach open data and license issues (hence the lack of an official license here). So please contact us and we can have a discussion there.
Without the general OpenSource GIS stack, this site would be nowhere near possible. We're super grateful for all of the contributors of said projects!