Golden Gate Bridge wanted it to be painted with black and yellow stripes to ensure visibility by passing ships. Senior engineer Charles Alton Ellis, collaborating remotely with Moisseiff, was the principal engineer of the project. Moisseiff produced the basic structural design, introducing his "deflection theory" by which a thin, flexible roadway would flex in the wind, greatly reducing stress by transmitting forces via suspension cables to the bridge towers. Although the Golden Gate Bridge design has proved sound, a later Moisseiff design, the original Tacoma Narrows Bridge, collapsed in a strong windstorm soon after it was completed, because of an unexpected aeroelastic flutter.
Golden Gate Bridge patterns. On weekday mornings, traffic flows mostly southbound into the city, so four of the six lanes run southbound. Conversely, on weekday afternoons, four lanes run northbound. During off-peak periods and weekends, traffic is split with three lanes in each direction. From 1968 to 2015, opposing traffic was separated by small, plastic pylons, and during that time, there were 16 fatalities resulting from 128 head-on collisions. To improve safety, the speed limit on the Golden Gate Bridge was reduced from on October 1, 1983. Although there had been discussion concerning the installation of a movable barrier since the 1980s, only