After determining that a cut-and-cover tunnel would not be feasible, a second series of public hearings to discuss the impact of an elevated option were held in 1970, leading to widespread controversy and a civil suit launched in opposition to the freeway.

The lawsuit ended in November 1971, with a King County Superior Court judge ruling that a major deviation from the voter-approved 1960 plan occurred, forcing a referendum to be held on whether to continue the project.

The roadway would have immediately merged with ramps connecting to the Roy and Mercer couplet and to a parking garage for a multipurpose domed stadium, later relocated and built south of Downtown in 1976,[4] to form the Bay Freeway.

[10] In anticipation of the Bay Freeway, underpasses of Aurora Avenue North on Broad and Mercer streets were completed in July 1958, using funds from a 1954 bond issue for the construction of arterial roadways.

[16][17] The Century 21 Exposition was hosted at the Seattle Center grounds from April to October 1962, generating heavy traffic equivalent to rush hour loads on Mercer Street, where a city-owned, 1,500-stall parking garage was located.

[18] The use of Mercer Street as one of the primary routes to the fairgrounds and its selection as one of the sites for a proposed multi-purpose stadium convinced city officials that the construction of the Bay Freeway was a necessity.

[24] The three proposed elevated alternatives were criticized by the public and local architects Ibsen Nelsen and Victor Steinbrueck for blocking views of Lake Union, forcing Morse to reconsider subsurface designs despite his declaration that "a depressed roadway with the freeway would require excessively steep traffic grades".

[30] The Seattle Center was selected as the preferred site of the multi-purpose domed stadium in 1968, assuming that the Bay Freeway was built to prevent event congestion, forcing the project to be redesigned for the next two years.

The report featured a new design for the freeway, including ramps to a parking garage serving the domed stadium and aesthetic standards meant to complement the existing Seattle Center.

[3] During the April hearing, former State Department of Highways director Charles Prahl spoke out against the Bay Freeway and predicted that it would cause traffic to back up onto I-5 during rush hour.

The two citizens groups opposed what they claimed was improper planning and financing, described as "a series of shortcut procedures and hearings to give the design rubber-stamp approval", and that the project did not conform to the voter-approved 1960 proposal for a "Mercer Street Connection".

A depressed roadway was rejected outright, as it could only achieve a grade of 6% at 3,000 feet (914.40 m), required a larger amount of right-of-way acquisition and relocation of utilities, and it was located below the water table, making it too expensive to be feasible.

State Highway Director George H. Andrews warned that the dual cancelation of the Bay Freeway and R.H. Thomson Expressway, the latter having been defeated on the same day,[2] would overload I-5 far beyond its design capacity, particularly in serving freight traffic near the Industrial District.