On the Golden Gate Bridge the lanes of opposing traffic are divided only by small rubbery posts called penguins. The penguins are about 18" tall, yellow, and have a strip of reflectorized material around the top. Each has a peg on the bottom which fits into a little hole in the asphalt. They are moved throughout the day by people called paddlers who are seated in a specially made pickup truck bed which allows one person to pull penguins out of their spots on one side, while another places them into the roadbed holes on the other. In this way the number of lanes going north or south are changed throughout the day to suit commute needs.
These penguins have no possibility of stopping any vehicle which might be traveling over the Golden Gate Bridge. Hence, in the two middle lanes, where traffic travels at least 45 miles per hour, there is nothing but penguins placed every ten feet or so as a barrier to oncoming traffic. These center lanes are the suicide lanes, where numerous gruesome and fatal accidents have occurred as a result of head-ons on the Bridge.