This machine has eliminated head-on collisions on the Golden Gate Bridge

The Road Zipper movable barrier system is proving that it can save lives on the Golden Gate Bridge. Since it was installed in 2015, there have been no head-on collisions. From 1970 until the system's installation, there were more than 100 such accidents, 16 of which were fatal.

The barrier is made up of 3,517 interlocking steel and concrete pieces. Each piece weighs 1,500 pounds and is 32 inches tall.

The system also helps with lane management. At peak times during the day, the Road Zipper will move the barrier about 10 feet over to open another lane of traffic. It's operated by two people and takes about a half hour to reverse a lane. The technology was developed by Lindsay Corporation and is also being used in cities including San Diego, Boston and Philadelphia. Installation on the Golden Gate Bridge cost $30 million.