The most critical point was the interpretation of Section 2(dc) of the Act. The court reasoned that the grade separator, which is an underpass set up to obviate traffic congestion and air pollution, constitutes a “facility for the public or a convenience for the public at large.” Since the statutory definition of “construction” in Section 2(dc) specifically excludes the provision of facilities of this nature for the public, the PMC’s work could not be regarded as prohibited construction under the Act.