Denver ambulances get 'ground-shaking' sirens to force drivers to yield

A dozen ambulances in Denver reportedly have been equipped with ground-shaking siren amplifiers to convince motorists to yield to emergency vehicles.

The 100/200-watt subwoofers, already on a dozen Denver Health ambulances, generate a frequency low enough to vibrate everything outside of the vehicle, the Denver Post reports.

"They vibrate the entire ground," Scott Bookman, chief paramedic for Denver Health EMS, told the newspaper. "People can feel it throughout their car. It's pretty neat."

Bookman said motorists don’t likely intend to hinder ambulances responding to an emergency call, but the problem of drivers refusing to yield was considerable enough to prompt the change. After 18 months of testing, Denver Health is now making the subwoofers standard issue for all new vehicles, Bookman said.

Denver Fire Department spokesman Phil Champagne said people “aren’t even connected to the outside world anymore” and warned that that ignorance can be fatal, citing an 80-year-old woman who died in January after she pulled out in front of a fire truck.

"I have seen people just keep going 30 mph with us right behind them, and there is no way they haven't noticed us," Champagne told the newspaper. "It is a matter of getting out of the way so we can do our job, but also realizing your car will not match up well against our trucks."

Click for more from the Denver Post.