Early versions of monorails utilized cumbersome in-track switches. These worked liked train switches and moved the entire track. Such switches were a weak link that made it impossible to design systems which had many closely spaced vehicles. An in-track switch must first move to the correct position, then verify that it is locked in that position and the vehicle must be able to stop before it reaches the switch if the verification is not obtained. In-track switches often consist of articulated straight pieces of guideway that swing back and forth.
Passengers feel a strong lateral jerk each time the vehicle passes one.
An in-vehicle switch permits the use of smooth curves, maximizing comfort and minimizing jerks. In-track switch sections are much larger than a simple branching sections. These switches also have one part of the track leading into empty space which is often disconcerting to passengers viewing it from their vehicle which is approaching at the rate of 30 miles per hour or more. Electro-magnetic switches have no moving parts and are simpler, more maintenance free and more reliable yet. This technology is currently in use in the most leading-edge material handling systems and amusement rides.