Practical use of self-driving cars requires changes to existing regulatory frameworks – or at least that’s what GM and Toyota are prepared to tell U.S. lawmakers on Tuesday, at a panel convened to review the state of self-driving regulation and proposed guidance on their use and testing set out last year by the National Highway Traffic Safety Administration (NHTSA).

GM and Toyota will testify that current regulatory conditions could negatively impact timelines for actual deployment of autonomous driving systems, delays to which GM says in a written version of its planned remarks seen by Reuters could result in “thousands of preventable deaths.” Toyota Research Institute’s Gill Pratt will tell the House panel that it’s “important the federal government begin looking beyond testing dot deployment of these systems.”

Lyft VP of Public Policy Joseph Okpaku is also set to address the forum, and will reiterate Lyft’s goal of fielding trials of its autonomous vehicle ride-hailing service in cities starting this year. Volvo VP of government affairs will share how the carmaker wanted to test its “Drive Me” pilot in the U.S. in addition to Sweden, but that it’s not currently set to go forward because of the uncertainty around the regulatory environment.

Part of the issues automakers want addressed is the current 2,500 vehicle cap per year from NHTSA rules for cars, which puts an effective cap on the size of autonomous vehicle fleets that can operate. That’s not the only regulatory hurdle the companies must clear, however, and the proposed NHTSA regulations have prompted some pushback from industry players, including notably Toyota, whose North American director of tech and innovation policy highlighted some of the major problems with the suggested rules last year.

Senator Gary Peters (D-MI) and Senator John Thune (R-SD) also announced on Monday that they will lead a joint effort to pursue legislation that “clears hurdles and advances innovation in self-driving technology.” New U.S. Secretary of Transportation Elaine Chao has also said she favours seeking partnerships with industry to find the way forward on issues including self-driving, and will seek to establish a regulatory framework that isn’t “dampening” the creativity of industry and innovation, while still respecting the privacy and safety of individuals.