The contrast of the runway markings was greatly reduced, in line with the textures of the surroundings, so that airports blend in much better. This airport is actually very difficult to find and pilots can fly right past it without finding it.
Two major highways go past the far end of the runway in real life, but due to registration errors between the FAA runway database and the road database one of them passes through the airport. This is just one example of the inaccuracies that make it dangerous to use FlightGear data in real life.
The improvements in scenery generation for visual flight can be seen in the river, valley and coastline and bay.