conuly

The article on suspended monorails starts out saying

the technical complexities of suspended monorails—particularly their vulnerability to weather conditions, difficulty in switching tracks, and structural requirements—made them suitable only for niche applications.

It then goes on to show the Chiba Urban Monorail system without mentioning that its design solves the first two of those problems. (It even has two lines which run together for the first three stations before splitting!)

The SAFEGE/SIPEM style of suspended monorail uses an enclosed box girder with a slot along the bottom; the trains' bogies ride inside the girder on rubber tires and the trains hang below them rather than riding above them as with a traditional train. This allows them to climb steeper slopes than a steel-on-steel system and protects the running surface from rain, snow, leaves, and all that.

Switching is done by having an internal pivoting plate (horizontal for SAFEGE, vertical for SIPEM) that moves the bogie in the correct direction.