Someone pointed out that the map says 500, not 800 km. It is actually 500 km (I just measured it on Google Maps),. But either way, it's impressive.
There is a road in central Brazil that is 311 miles long. Big deal you say? We are talking about a street, one street, that stretches the equivalent of New York City to Albany, and back, or from San Diego to Las Vegas. That's a huge freaking road. What makes it a road, and not a highway? Notice that there are streets branching off of it the whole way. There are also houses all along it. This isn't a road from point a to b, it is a residential street.