Looks like all of your yellow cars were stuck in a traffic jam by the traffic lights crossing. Was highway 2 a fairly recent addition?
One problem I run into myself is that it takes a LOT of time for an attempted fix to actually work and most of the time it’s already too late. In mini metro you could throw an extra train on a line or toss another carriage or two at a troublesome station and get a little leeway to figure out a more sustainable solution. Even massive redraws of your lines were possible to be accomplished in very little effective time. But in this game you have to prevent a problem before it is a problem.
Absolute disaster is the unavoidable end state.