Which of the following can be a consequence of excessive bus idling?

Excessive bus idling can lead to increased maintenance costs for several reasons. When a bus is left running for extended periods, the engine, exhaust systems, and other mechanical components are subjected to wear and tear. The additional operational time contributes to a greater accumulation of dirt and contaminants in the engine and components, which can result in more frequent maintenance needs such as oil changes, filter replacements, and overall service. Furthermore, running the engine while stationary can create unnecessary stress on the engine and associated systems, potentially leading to premature failures or the need for repairs that could have been avoided with proper idling management practices. This not only incurs direct costs but can also lead to operational inefficiencies due to increased downtime while repairs are made.

In contrast, the other options suggest benefits that do not typically arise from excessive idling. Passenger experience is likely to be hindered due to noise, emissions, and potential dissatisfaction. Community relations could suffer as well, as excessive idling contributes to air pollution and noise pollution, which are concerns for residents in the vicinity. Finally, higher fuel efficiency is contrary to the effects of idling; in fact, excessive idling often leads to fuel wastage rather than efficiency.