In one particularly hilarious scene in the TV show Weeds, Mary-Louise Parker’s soccer mom/drug dealer character inspires a scary drug lord to buy several Toyota Priuses after he successfully carries out a drive-by shooting while riding in hers. 

The selling point? The quietness of the hybrid. “Good for sneaking up on mother******s,” he cackles.

That might no longer be the case with a piece of legislation that recently passed the Senate and looks to be cleared for approval in the House. The Pedestrian Safety Enhancement Act would require electric cars and hybrids to make noise, and would fund the Department of Transportation to create a set of rules for automakers, who would be allowed some leeway in how they carry out the guidelines.

Green cars like the Prius don’t make noise when running off their batteries. Whether you have an armed drug dealer as an enemy or (more likely) happen to cross the street without looking, hybrids are more likely to hit you than regular cars, especially when operating at low speeds when gas engines aren’t engaged, according to a study by the National Highway Traffic Safety Administration. All-electric vehicles like the 2011 Nissan Leaf could be even more of a threat.

New bill could make hybrid cars noisy to protect blind

New bill could make hybrid cars noisy to protect blind

Of particular concern was the potential danger to blind pedestrians. But researchers and writers have also challenged that study, saying the methodology was flawed.

Automakers have tried their own cures for the issue. The 2011 Chevrolet Volt has tried to ward off this problem with a quieter horn built into the car — you pull the turn signal towards you, and it emits a muffled, friendlier honk that workers internally call “the hybrid hello.” The Nissan Leaf automatically makes noise after you go over 12 miles an hour.

Lotus Engineering has created a “spaceship-sounding” system that can be installed in the Prius. As Green Car Reports notes, the legislation would allow for a common set of standards, rather than than a motley crew of approaches attempted by various automakers.

One opportunity for automotive marketers and startups is the emerging business of supplying drivetones, the automotive equivalent of cell-phone ringtones. Want your green car to rev like a Ferrari or BMW? Just buy the right drivetone and crank up the exterior volume.

There’s been some argument over whether or not the legislation is really necessary — if the original government study was wrong, then maybe not. But if it’ll make pedestrians safer at no great cost to the electric car industry, it’s hard to see how this will hurt beyond the annoyances of government bureaucracy.

Either way, it looks like fictional drug warlords will be out one weapon.

This story, written by Iris Kuo, was originally posted on VentureBeat's GreenBeat, an editorial partner of GreenCarReports.