“…Therefore, the expected sign of α 4 is positive. Also, R&D has been investigated as a potential factor of CO 2 emissions, and it lowers environmental pollution (Dauda, Long, Mensah, & Salman, 2019;Mensah, Long, Boamah, Bediako, & Dauda, 2018 (Ahmed, Wang, Mahmood, Hafeez, & Ali, 2019). The transport sector is measure as freight transport, refers to a total number of goods through domestic transport within a given network.…”