the Golden Gate Zipper Technology of Dividing !!

In Jan 2015,  San Francisco’s Golden Gate Bridge closed down for the bridge’s longest shutdown ever and its first closure in more than 25 years.  It was closed to enable workers  install a moveable median barrier to prevent head-on collisions, according to a statement on the bridge’s website.  The bridge closed briefly in 1987 to celebrate its 50th anniversary, but the 52-hour closure  was the longest in the bridge’s history and was the first in 77 years !!!  While the road was closed to vehicles, with the exception of emergency vehicles and Golden Gate Transit buses, the sidewalks remained open to pedestrians and cyclists ~and that was recorded for posterity by many taking selfies !!! Amidst the bustling traffic of Chennai, there are few roads that one can drive freely [sort of !] ... the Kamarajar Salai  aka Beach Road is somewhat better – though a very busy stretch right from the mornings.  To ensure free flow of traffic, the Police made a study and observed that in the mornings, the flow towards Fort St. George is more and in the evening it is in the return direction.  So, they move the plastic barriers to 3/4^th of the road – allowing more width for one side of the traffic – traffic diversions into the inner beach road are also done at many a times. The Golden Gate Bridge is a suspension bridge spanning the Golden Gate strait, the mile-wide, three-mile-long channel between San Francisco Bay and the Pacific Ocean. The structure links the U.S. city of San Francisco, on the northern tip of the San Francisco Peninsula, to Marin County, bridging both U.S. Route 101 and California State Route 1 across the strait. The bridge is one of the most internationally recognized symbols of San Francisco, California, and the United States.   Before the bridge was built, the only practical short route between San Francisco and what is now Marin County was by boat across a section of San Francisco Bay. Ferry service began as early as 1820, with regularly scheduled service beginning in the 1840s for purposes of transporting water to San Francisco. Although the idea of a bridge spanning the Golden Gate was not new, the proposal that eventually took hold was made in a 1916 San Francisco Bulletin article by former engineering student James Wilkins.  The bridge's name was first used when the project was initially discussed in 1917.   The bridge-opening celebration began on May 27, 1937 and lasted for one week. The day before vehicle traffic was allowed, 200,000 people crossed either on foot or on roller skates.  In May 1987, as part of the 50th anniversary celebration, the Golden Gate Bridge district again closed the bridge to automobile traffic and allowed pedestrians to cross the bridge. Here is something on the mesmerizing Golden Grate Bridge 'zipper truck' that lays out $30million safety barrier every day.  MailOnline reports that for  50 years, lanes were divided by lines of small plastic tubes; now a flexible barrier has been set up and can be moved by the vehicle.   Every day, their direction and positioning changes to account for commuter traffic, meaning an employee had to go through the arduous task every 24 hours.   The new piece of mesmerizing machinery means the traffic set up the 1.7-mile San Francisco structure can be completed in a matter of minutes. This 'zipper truck' can move recently-installed safety barriers across the San Francisco structure in a matter of minutes.  The flexible partition that was put in during maintenance work stopover was designed in a bid to reduce head-on collisions. The zipper truck moves the barrier to another lane location. It is said to have cost around $30million.  Dr. Grace Dammann, who pushed for a safer median barrier since becoming paralyzed from the crash, said she decided to drive in the 'suicide lane' because she and her daughter were running late. Brian Clark, who was driving in the opposite direction, had just learned his father had terminal cancer. 'He passed out at the wheel, crossed over and hit my car,' Dammann recalled. She said she and Clark became friends as they urged the district to approve the $30 million barrier. 'I am so grateful,' said Dammann, who came to the ribbon-cutting ceremony with Clark. 'Brian and I thank you.' With regards – S. Sampathkumar
9^th April 2015.