An autonomous demand-responsive transit with mobility-on-demand (MoD) service is an emerging technology to accommodate many travelers with autonomous vehicles (AVs) in congested areas. The MoDA DRT bus can efficiently mitigate the risks of driver fatigue by the frequent routing changes and massive demand induced by the other transportation modes. The MoDA DRT bus has the potential to reduce air pollutants by itself, but less attention has been paid to network-level air pollutant reduction. This paper quantifies the link energy consumption of the road network by introducing the MoDA DRT bus through the microscopic traffic simulation. This paper sets up the four scenarios of different types of MoDA DRT buses to identify the gas emission and electricity consumption in the road network. The results found 8.15 % decrease in CO2 of the introduction of MoDA DRT bus as well as the environmental impact of the adoption of EVs. The results also showed the importance of relieving the MoDA DRT bus speed limit to maximize the environmental benefits. This study helps policymakers introduce the MoDA DRT bus by considering the environmental impacts of the road network itself.