In January, General Motors unveiled the Cruise AV, a car designed to have no steering wheel and no gas or brake pedals. It seems like science fiction, but GM is completely serious about the project. On Wednesday, GM announced that it is investing $100 million in manufacturing facilities for the new car, with a goal of introducing a commercial taxi service using the vehicles by the end of next year.

But how quickly these cars actually show up on our roads will depend on Congress. Current safety rules require every car to have a steering wheel and pedals—making a car like the Cruise AV illegal without a special exemption. The rules can be changed by regulators, but the rulemaking process typically takes years to complete. So car and technology companies have been lobbying Congress for an expedited process to allow tens of thousands of vehicles like the Cruise AV on the roads ahead of a full rewrite of the safety regulations.

The House of Representatives easily passed a version of this legislation, called the SELF DRIVE Act, last September. But the Senate's companion legislation, known as the AV START Act, has been making slow progress. With midterm elections looming, insiders say the next few months are crucial. If the Senate doesn't pass the AV START Act soon, large-scale manufacturing of vehicles like the Cruise AV could be pushed well into the next decade.

Critics of the legislation say that wouldn't be a bad thing. They argue that rulemaking is slow and deliberate because that's what's required to protect public safety. They point out that there are plenty of avenues for companies to test driverless car technology under existing rules in the meantime.

But advocates warn that delaying the introduction of driverless cars could easily cost many more lives than it saves. Errors by human drivers lead to crashes that kill tens of thousands of Americans every year. Driverless cars may be able to prevent many of those deaths. So slowing progress on driverless car technology—even by a year or two—could cost thousands of lives.

"The rate at which the public will realize the benefits of fully autonomous vehicles will be delayed if we have these regulatory barriers in place," says Greg Rogers, an analyst at the energy policy group Securing America's Future Energy (SAFE).

Waymo abandoned plans to nix steering wheel

The big obstacle to introducing a fully driverless vehicle like the Cruise AV is a set of rules known as the Federal Motor Vehicle Safety Standards (FMVSS). These regulations specify, in excruciating detail, the safety standards that must be met by every major component of an American car.

Many of these regulations were written decades ago, and their authors likely never considered the possibility that a car might not have a human driver at all. As a result, the regulations have requirements that don't make sense for a fully autonomous car, like steering wheels, gas pedals, brake pedals, controls for turn signals, rearview and side view mirrors, and so forth. And it's not just that these features are unnecessary—a human passenger unexpectedly grabbing the wheel of a fully autonomous car could easily cause a crash.

The first company to grapple with this issue was Google. Back in 2015, the company had designed a small two-seat driverless vehicle, dubbed the Firefly, with no steering wheel, pedals, or other driver controls. The company's lawyers warned that introducing the Firefly as a commercial product could get Google in legal trouble.

So Google wrote to the National Highway Traffic Safety Administration (NHTSA), the agency responsible for updating and enforcing the FMVSS. Google asked the NHTSA for permission to treat the self-driving software as "the driver" for purposes of FMVSS requirements. The company also asked for permission to ignore provisions of the FMVSS that related to a human driver, arguing that these regulations were inapplicable since a Google self-driving car wouldn't have a human driver.

NHTSA was OK with treating Google's software as "the driver" when interpreting the FMVSS. But NHTSA said no to ignoring explicit requirements for human-accessible controls. For example, one rule requires that a brake "shall be activated by means of a foot control." Google could ask the NHTSA to open a formal rulemaking procedure to change these rules. Google could also request a special exemption from the rules—with some important limitations we'll discuss below. But the NHTSA said that simply pretending the rules weren't there wasn't an option.

This turned out to be a moot issue because the NHTSA's letter arrived as Google's driverless car program was undergoing a major leadership change. Google ousted Chris Urmson as head of the driverless car project in favor of auto industry veteran John Krafcik. Under Krafcik's leadership, Google abandoned the idea of designing its own car from scratch. Instead, the company began negotiating with incumbent car companies—first Ford, then Fiat Chysler—to buy standard human-driver cars that could be modified for driverless applications.

This new strategy has allowed Google—now Waymo—to sidestep the FMVSS issue. Waymo buys standard Chrysler Pacifica minivans that are already compliant with the FMVSS, then outfits them with sensors and other driverless car hardware. Waymo's plan is to leave the driver controls in the cars but not let anyone touch them.

This will likely allow Waymo to bring a driverless taxi service to market without needing any changes to the FMVSS or special approval from the NHTSA. But it's obviously a clumsy solution. It means one of the seats on each vehicle is essentially unusable. And Waymo has to worry about passengers—perhaps a rowdy teenager or a passenger who has had too much to drink—grabbing the wheel at the wrong moment and possibly causing an accident.