How many time has that happened in WDW in the last 44 years?Yes one bus accident can shut down an entire highway. I have been on highways stuck behind an accident for hours.
How many time has a monorail shut down an entire rail in the last year?
A bus crash shutting down an entire transportation route is a once in a century anomaly.
A monorail simply breaking down and shutting down an entire route is a monthly inevitability.