Smart Technologies Advancing Reliable Transportation Act or the START Act This bill directs the Department of Transportation (DOT), in coordination with the Department of Energy, the Department of Housing and Urban Development, and the National Science Foundation, to create, publish, and maintain a resource guide to assist states, communities, and cities in developing and implementing smart city or community programs. DOT shall develop and implement an additional round to the Smart Cities Challenge, under which it shall provide competitive grants to small- and medium-sized communities to implement smart transportation proposals. The Government Accountability Office shall conduct a study on innovative financing and procurement for funding smart cities or community activities and associated demonstration projects. Recipients of a Smart Cities Challenge grant shall submit quarterly reports to DOT regarding the development, implementation, and operation of their projects funded under the challenge.