For long distance driving speed is key. Highways can be faster even when they are indirect. This is what the OSMAnd "Fuel Efficient Way" routing is based on. It

For long distance driving speed is key. Highways can be faster even when they are indirect. This is what the OSMAnd "Fuel Efficient Way" routing is based on. It biases towards the shortest routes that may have lower speed limits. This is nice for road trips and bicycling, but can be quirky with city driving.