Overwhelming evidence throughout the literature has shown that bus
overhead and maintenance (O&M) costs increase as buses age. This has
implications toward a fleet manager’s decision of when one should buy, use,
or sell buses to minimize total fleet costs. Unfortunately, there are uncertain
market conditions associated with bus fleets that cloud the manager’s ability
to make appropriate decisions. Using integer programming (IP), O&M trends
and changing market conditions are integrated into a model to better analyze
bus fleets.