It depends on how long these sections are. We're probably of the same mind but thinking of different dimensions. If we're talking just for electrified sections

It depends on how long these sections are. We're probably of the same mind but thinking of different dimensions. If we're talking just for electrified sections of up to 2 km, alternating a dozen times or more, I'm not sure if it's worth it. For longer sections, yes, it's an absolute killer feature. The cost of raising the panto slightly too early even once is tremendous. You would have to close the track for maintenance. So you need a safety margin of a few seconds. That's several 100 meters. Frequent changeovers would necessitate the system to be fully automated in order to factor out human error. The changeover on London Overground is usually done while standing at a station (by the driver). According to [1] it's possible to switch while moving. The speed limit is given as 25mph, however. [1] https://www.railforums.co.uk/threads/changing-from-dc-to-ac-whilst-moving.60417/ https://www.railforums.co.uk/threads/changing-from-dc-to-ac-...