The cost of public transport has increased more than the supply in recent years in Sweden. One of the main cost drivers identified is peak-hour traffic. The major operating cost factors are the need for a large bus fleet for short periods during mornings and afternoons and the scheduling of drivers for shorter periods than the minimum working hour restriction. The objective of this paper is to study the effect of the number of buses needed (and hence the operating cost) during peak hours when adjusting the bus departure times. The study also analyses the increase in public transport supply and the number of boarding passengers if the cost reduction is re-invested. The analysis is based on case studies and simulated scenarios of possible adjustments in departure times for buses. The results show that by marginally adjusting the departure times, fewer buses are needed which leads to decreased operating costs. Further, the results show that the reduction in costs can be used to improve public transport in the area by expanding the supply of public transport in the long run.