The average distance between station is smaller than most IC trains in most other countries, but frequencies are higher. All lines are served at least with 2tph, but many busy stretches are served have 4tph. From Utrecht Central there are even two different services to Amsterdam, one that serves the central station and two others and another that serves the south station and the airport. From December 2017 the frequency between Amsterdam, Utrecht and Eindhoven will be further increased to 6tph.