Allow under construction electrified rail to be traversed

I always wished I could upgrade my rail network in a realistic manner. Most countries have electrified and unelectrified corridors depending on local conditions and corridor utilization. But building track in W&R is such a ballache that I'd rather just electrify everything from the start, since I don't know where I eventually want to use electric locomotives.

I'm not a rail engineer, but I've done a bit of digging. And like I suspected, real work electrification projects don't completely shut down a track segment until completion. Sure, trains can't use the track while construction is happening, but the crew clear off at a scheduled time and diesel trains can merrily plow past the pylons.

So I'd recommend that upgrading concrete to electrified rail still allows the tracks to be used, maybe with a lower speed limit. Track builders already do this by slowly traveling down an under construction track to reach where they left off, so I think the engine would allow for this sort of thing. And it would make manual rail construction at most half the headache