StateEditor s1 = s0.edit(this);
s1.setTimeSeconds(alight_before);
long wait_cost = t0 - alight_before;
s1.incrementWeight(wait_cost + transfer_penalty);
s1.setBackMode(getMode());
return s1.makeState();
} else {
/* Forward traversal: not so much to do */
StateEditor s1 = s0.edit(this);
TransitStop toVertex = (TransitStop) getToVertex();
s1.alightTransit();