5. Special lanes

5.1 Rubber-tyred metro track

The operation of certain metro lines, where traffic is particularly dense, requires very high acceleration rates - positive for traction and negative for braking - in order to reduce the distances between trains. Conventional wheel-rail adhesion does not allow for such performance, so we have resorted to rolling on tires, which provide a much higher coefficient of adhesion, of the order of 60 to 70%. The first application was on Paris metro line n° 11 Châtelet – Porte des Lilas in 1954:

• the rolling function is provided by two flat tracks, formed by special I-sections, for wheels fitted with pneumatic tires. As the profile of these wheels is cylindrical, a differential is interposed on the axle axis to replace...