<P> The main problem with a train on tram rails is the relatively narrow width of frog and switch gaps and channels of the groove rails designed to accommodate the narrow flanges of tram wheels . The wider flanges of train wheels increase the risk of derailment at these points . On routes where train carriages are driven on tram tracks (as in the past in parts of The Hague), wider grooves are required as a compromise that is practical as wide grooved girder rail is available . A larger structure gauge would also be required This was also done in Los Angeles and in Vancouver as well as elsewhere in North America . The usually or normally limited structure gauge, and tight curves, on tram tracks will also prevent trains from using tram tracks . </P> <P> In North America the groove would have to be a minimum of 2 ⁄ in (54 mm) wide and by extension, the maximum distance between the inside faces of the guard flanges of the grooved rails can be no more than 52 ⁄ in (1,327.1 mm), see below . </P> <P> 1 . Lateral tolerance between wheels and rails Two types of flanges are permitted on railroad wheels - narrow and wide . The maximum lateral movement T1 possible for a new wheel set centered on in - gage track is a function of the flange type and is determined by the following formula: CAUTION: Use only English Units in Formulas in this Recommended Practice </P> <P> Where: gt = standard track gage at a point "5 / 8" (15.9 mm) below top of rail = 56.5" (1,435.1 mm) </P>

Whats the difference between a train and a tram