As public transport operators try to resume their services, they have to operate under reduced capacities due to COVID-19 . Because demand can exceed capacity at different areas and across different times of the day, drivers have to refuse passenger boardings at specific stops . Towards this goal, many public transport operators have modified their service routes by avoiding to serve stops with high passenger demand at specific times of the day . Given the urgent need to develop decision support tools that can prevent the overcrowding of vehicles, this study introduces a dynamic integer nonlinear program that proposes service patterns to individual vehicles that are ready to be dispatched . In addition to the objective of satisfying the imposed vehicle capacity due to COVID-19, the proposed service pattern model caters for the waiting time of passengers . Our model is tested in a bus line connecting the university of Twente with its surrounding cities demonstrating the improvement in terms of vehicle overcrowding, and analyzing the potential negative effects related to unserved passenger demand and excessive waiting times.