Recent technological advancements have allowed trains to reach much higher speeds than was previously possible. This has raised concerns about excessive displacements and track vibrations, which present safety concerns and can also affect structures near the track. High-speed trains typically run on traditional ballasted lines, often leading to high maintenance costs due to accelerated fouling. Ballastless systems such as concrete slab track present a possible solution to this issue. Although they incur higher construction costs, they generally require less maintenance and have lower life-cycle costs. The rail industry is interested in other potential benefits of using slab track such as better vibration performance. The paper analyses the behaviour of an industry typical concrete slab track using a 2D Finite Element Model. A parametric study is conducted to quantify the vibrational effects of changing the stiffness of the soil underlying the track and the train speed. Slab track performance is then compared to a typical ballasted track. The slab track is shown to more effectively reduce train-induced vibrations. Track level displacements in slab track are, on average, 47% lower than those of the ballasted track. Subsoil surface displacements are 41% lower.