How reliable are the bus timetables for the metro system in los angeles?

I'm trying to figure out how long it would take to get from mid-Wilshire/ Koreatown area to UCLA campus using public transportation. I know Wilshire blvd gets really blocked up, but I'd like an estimate. metro trip planner gives timetables estimating between 20-45 minutes, but is that really reliable? Any input is appreciated. thanks!|||The higher end of that range sounds about right.|||iits prettily good it could take longer sometime but 45- 50 sounds about right