However, the bill died after a House–Senate conference committee was unable to agree whether to allow Highway Trust Funds to be used for mass transit.

[4] Second, the death of Democratic Representative Hale Boggs, the House Majority Leader, in a plane crash in Alaska on October 16, 1972,[5] elevated Thomas P. "Tip" O'Neill to that position when the new 93rd Congress convened in January 1973.

On March 14, the Senate voted to give states the authority to use up to $850 million of Highway Trust Fund money in both 1973 and 1974 for the expansion or construction of mass transit.

In 1972, Representative Colmer had used his role as chair of the Rules Committee to block any floor amendments aimed at adding mass transit spending to the 1972 highway bill.

The committee was populated primarily by members of Congress from rural areas who wanted to expend money on highways and were not willing to devote funds to the construction of mass transit (which benefitted only cities).

[9] Representative Glenn M. Anderson, Democrat from California, offered an amendment in committee to allow cities to use their $700-million per year share of funding for urban highways on mass transit.

[9] For the first time in many years, the bill did not contain very much language earmarking funds for or requiring states to build specific construction projects.

It did contain, however, provisions requiring the Department of Transportation (DOT) to establish a program on highway safety research and design improvement.

[11] Anderson submitted his mass transit amendment when the Public Works bill came up on the floor of the full House of Representatives in late April 1973.

Senate conferees offered a compromise, based on suggestions made by President Richard Nixon and Representative Donald H. Clausen (a Republican from California).

The Senate also agreed to ease requirements that states meet certain civil rights and environmental standards, which would allow a number of highway construction projects which had been held up to move forward.

[7] The House was reluctant to agree to such a measure, since it would only lead to higher pressure over time for a compromise on the mass transit issue.

[12] But with states running out of money, the House passed by voice vote a $1.5 billion highway aid continuing resolution.

In fiscal year 1976, states could divert up to the entire $800 million urban highway appropriation to mass transit (which now included not only buses but also rolling stock as well as rail construction).

The conferees also agreed to bar states from canceling sections of their planned interstates to use the money for mass transit.