Tropes on a Bus
"...go round and round, round and round, round and round. The Tropes on a Bus..."

In trope-speak, a "bus" is a metaphorical device that effortlessly transports characters away from the plot for a long time. Often permanently.

Front-Line Fleet (tropes that directly reference the metaphorical bus).

Backup Fleet (these refer to buses, but not in that way).