A diverse group of public interest organizations is urging Senate leaders to not advance legislation loosening restrictions on the development and deployment of self-driving vehicles until self-described safety flaws are corrected.

In a letter to Senate Majority Leader Mitch McConnell and Democratic leader Charles Schumer, the coalition said automotive and technology companies have misled the public about how soon automated vehicles will be widely available and how regulation is an impediment to innovation in the global race to harness mobility solutions with the potential to reduce traffic fatalities, congestion and air pollution.

“Baseless and exaggerated predictions about the readiness and reliability of driverless car technology are propelling legislation that significantly strips the current federal regulatory system of its appropriate authority and oversight thereby endangering the safety of everyone — both motorists and non-motorists,” said the 27 signatories, representing public health and safety, bicyclists, pedestrians, consumers, disability communities, law enforcement, environmentalists, first responders, smart-growth advocates and crash victims’ families.

An alliance of 105 AV START Act supporters — including automakers, car rental companies, wireless communication and high-tech interests, suppliers, and other groups — fired back Monday afternoon with a letter of their own, encouraging the Senate to move faster on getting the bill passed.

Many of the groups have been fighting the AV START Act since last year, arguing that it gives too much freedom to industry at the expense of safety.

The letter also raises a new concern: that autonomous vehicle technology is so far unable to accurately detect and react to bicyclists.

Autonomous vehicle interests are eager for Congress to pass policies governing development and testing of the technology to guard against proliferation of inconsistent state laws or a heavy federal response to a deadly accident that could jeopardize their investments.

One of their primary asks is for more exemptions to federal motor vehicle safety regulations to expedite evaluations of new technology. Industry players say the artificial intelligence guiding vehicles will self-improve the more it is exposed to real-world driving conditions.

The AV START Act, which several Democrats are holding up from consideration by unanimous consent, would authorize the Department of Transportation to grant exemptions for up to 80,000 vehicles per manufacturer after three years.

Under current law, manufacturers can petition for exemptions to sell up to 2,500 cars per vehicle per year for two years, if the technology provides safety or impact protection at levels equal to or better than the existing standard. Since 1994, there have been only eight such requests and NHTSA, the nation’s auto safety regulator, has generally denied the petitions because they failed to show that the proposed safety features would be an improvement, according to a 2017 RAND Corp. study.

“Allowing the public sale of unproven autonomous vehicle technologies, granting automakers broad and unsafe exemptions from existing federal standards, and ignoring the need for the U.S. DOT to issue minimum safety requirements to address real problems will have disastrous consequences for public safety and public acceptance of driverless cars. We therefore urge you to put public safety first and reject the bogus claims of urgency by some automakers,” the public interest groups wrote.

Proposed improvements to the bill, many of which reiterate long-held positions, include:

• Reducing the number of vehicles allowed exemptions from safety standards since they will be sold to the public.

• Removing provisions that preempt states and localities from regulating driving systems until NHTSA develops federal standards and regulations.

• Removing language that gives manufacturers complete freedom to disable vehicle systems, such as the steering wheel, at their own discretion.

• Establishing minimum performance standards for the computers that operate autonomous vehicles, including a “vision test” for determining whether the system can identify other cars, pedestrians, traffic signs and other surroundings.

• Requiring consumers be educated about the limitations and capabilities of self-driving cars at the point of sale.

• Increasing NHTSA’s budget so it can adequately take on extra mission of regulating autonomous vehicles.