By Allen Martin

SAN FRANCISCO (CBS SF) — From the dramatic crash of the plane in Taiwan to the meteor streaking across the sky in Russia, dash cams have captured it all. In San Francisco, Muni calls it DriveCam — and passengers can expect more vehicles to start using them.

“It shortens a lot of conversations when you simply say, ‘oh I have a video to show you’,” said Muni Director of Transit John Haley.

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He said DriveCam is an invaluable training tool for drivers, recording countless close calls. In one instance, a woman steps right in front of a bus on Market Street.

When Muni started using DriveCam three years ago, Haley said there was some push back.

“We could have done a better job of preparing everybody, including the drivers and the collective bargaining units that were affected by it,” he said.

Drivers, passengers and other motorists have since found out DriveCam’s use is a two-way street. One clip shows a car seemingly oblivious to the bus.

DriveCam also catches Muni drivers making mistakes or behaving badly. The agency cites personnel and union concerns for not releasing that video.

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But another driver’s DashCam was posted on YouTube showing a Muni bus running a red light on Park Presidio just as an oncoming car slams on its brakes.

Haley said video evidence or not, one accident doesn’t mean a Muni driver gets fired.

“Oh no,” he said. “We have a very well defined collective bargaining agreement and a process for that and we of course follow that process to the letter.”

And the company that makes DriveCam says Muni bus accidents were cut in half the first year they were used.

Muni has new buses on order that will have even more cameras.

“In another month we will have our fourth new procurement in 18 months,” Haley said. “And each of those coaches will have 12 cameras, including DriveCam.”

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Muni points out DriveCam doesn’t work like the other surveillance cameras on board. It only starts recording when sensors detect a problem, such as when the driver slams on the brakes, or if there’s a crash.