Dynamics of travelers' modality style in the presence of mobility-on-demand services

•We investigate the dynamics of modal preferences while the MoD services operate.•This study uses the 2017 National Household Travel Survey data.•We utilized the MDCEV formulation to consider marginal rates of substitution.•The substitution relationship between transit and MoD is highly context dependent.•A pro-active approach to planning towards Smart Cities will be vital.