Keeping Utah Moving 

Traffic signal operation in Utah has evolved from a humble wooden box to a sophisticated digital network, but its roots are deeply local. In 1912, Salt Lake City police officer Lester Wire invented the world's first electric traffic light. As the head of the city’s first traffic squad, he created the device to protect officers from the dangers of directing cars manually.  Located at the intersection of Main Street and 200 South, this early device resembled a birdhouse with bulbs dipped in red and green paint, requiring an officer to sit in a roadside booth and manually flip a switch to change the colors.

Today, that manual switch is a relic of the past, replaced by a high-tech ecosystem where safety meets speed. Modern signals are powerful computers connected by a statewide fiber-optic network, allowing over 95% of state and city signals to communicate with a central system rather than operating as isolated islands. Instead of relying on fixed timers, signals utilize approach detection to respond to real-time traffic demand, coupled with Automated Traffic Signal Performance Measures (ATSPM). This technology allows the signals to "self-diagnose," reporting their own health and efficiency to engineers and automatically flagging issues like broken detection cameras or wasted green time. 

While the technology is automated, the system is actively managed by human experts at the Traffic Operations Center (TOC). Engineers and operators monitor the grid 24/7, making real-time adjustments for unexpected events like crashes on I-15, heavy winter storms, or the sudden rush of traffic following a Jazz game. This allows them to proactively tweak signal timing to maintain flow and safety, continuing Lester Wire’s mission using the tools of the modern age.