On lots of satnavs (including the above mentioned Tomtom), the driving instruction would be something like "at the intersection, turn right", as if at a crossing between two main roads. (that happens even in regions where the map data is more complete). On pure maps, the instruction is a bit more logical similar to "turn right to remain on {main street name}" (making it clear that you follow the main road on it twist and avoid taking a small side path).