How does that affect the question of whether the network is densely packed or whether it has frequent trains? Passenger trains from Frankfurt to Cologne are in

How does that affect the question of whether the network is densely packed or whether it has frequent trains? Passenger trains from Frankfurt to Cologne are infrequent because there is virtually no demand to move between cities 120 miles apart. Because the trains are infrequent, they aren't dense on the tracks. But that's the opposite of saying that they are frequent and densely packed.