Zoom allows the user to zoom in and out when using the Drivers' Eye View. This can compensate for the limited resolution of the computer monitor screen, and hence, the apparent poor performance of Visirail. Although the Visirail barriers are exactly drawn, the screen may show the through visibility ceasing after only a relatively poor distance. Using ZOOMx2, etc. can simulate binoculars, enabling the user to look at barrier rails in the distance and determine what visibility can be obtained through them. ZOOMx1 will return the view to that normally seen.