Split a switch ... for some reason that's a much bigger deal with "light rail vehicles" than it used to be with streetcars. With streetcars, as long as they were still on the track (I've seen a PCC in SF split the switch to the point where the car was nearly at right angles to one track) they could just back it out and try again. With LRVs, any little bump derails it and you need heavy equipment to re-rail (remember cars with a rerailing frog as part of the on-board tool set?). There used to be grooves in the pavement at the end of the wye tracks at the end of the J line where cars had gone a bit too far - but if one truck was still on the tracks (for electrical contact) they just reversed and backed it out.

In Sac, I've been on one low-speed derailment (hmmm ... why so slow? we shouldn't be diverging here! slow bump rumble rumble we're on the ground) and seen another due to split switches; in the first case it took all day (derailment happened around 0630) to get the car cleared away and inspect track and fix the switch (which was already known to be having problems when we got there in the morning given the number of work trucks present and driver behavior). They were still busing us from the prior inbound station at 1700 going home. In the other, at the lead to a little yard used for daytime storage, it was on pavement but the car got very sideways; needed a crane to pick it up and rerail it; again, down nearly all day and it really plugged the system being at a central location. Light Rail (generically) can't afford that - it needs to be more resistant to ordinary glitches and more easily fixable when something minor does go wrong. Maybe they should go back to the single carbody-two trucks streetcar and MU arrangement which seems more stable and forgiving of odd track conditions than the typical 3-truck-articulated LRV.

Hope Seattle can fix it faster than I've seen it done. At least, being at the "barn," the necessary equipment shouldn't be too far away.