Curve widening is performed by first looking up the inside and outside transition lengths and widths using the radius of the curve. Using this table, if the radius or the curve was 750 meters, the table values would be those of the next smaller radius, in this case, 700 meters or widths and transition lengths of 3, 150, 3, and 150 respectively. Once the values have been determined, then at each curve within the station range, the applicable width is added to the specified line by creating 3 horizontal point controls. The first and last controls are transitions from the current offset of the point from the controlling alignment to an offset of the current offset plus the widening width. The start and stop locations of these transition controls are determined by the transition properties from the dialog. The middle horizontal control is at a constant offset of the current point offset plus the widening width.