September 22

Events - Transportation & Infrastructure

1953day.year

The Four Level Interchange, first stack interchange in the world opened in Los Angeles.

The world's first stack interchange, the Four Level Interchange in Los Angeles, opened in 1953, revolutionizing urban traffic flow.
On September 22, 1953, the Four Level Interchange at the junction of US Route 101 and State Route 110 debuted in downtown Los Angeles. Designed by engineers Lloyd Aldrich and colleagues, it pioneered the modern stack interchange concept. Four separate levels routed traffic in all directions, eliminating weaving and significantly reducing congestion. Its innovative design influenced highway planning worldwide and became an iconic symbol of postwar American infrastructure. The interchange's complex steel-and-concrete structure demonstrated new possibilities in large-scale civil engineering. Today, it remains a vital artery in LA's freeway system and a milestone in transportation history.
1953 Four Level Interchange stack interchange Los Angeles
2006day.year

Twenty-three people were killed in a maglev train collision in Lathen, Germany.

On September 22, 2006, a Transrapid maglev train in Lathen, Germany, collided with a maintenance vehicle, resulting in 23 fatalities.
On September 22, 2006, a Transrapid maglev train on the test track near Lathen collided head-on with a maintenance vehicle on the guideway. The collision occurred at high speed, tearing the train apart and causing 23 deaths, including engineers and technicians. Investigators found that a dispatcher inadvertently authorized the train onto the occupied track. The accident marked the deadliest incident in maglev history and cast doubt on the system's safety. German authorities suspended the Transrapid program pending further safety reviews. The disaster prompted upgrades to signaling protocols and stricter track monitoring measures.
2006 maglev train collision Lathen Germany