There are 2,857 traffic signals across Miami-Dade County. Some days it feels like you’ve hit them all. Last month, the Miami Herald Editorial Board launched its traffic initiative — H*ll on Wheels — asking readers to share their gridlock grind. We promised to get answers to the problems they identified.
Up first is the most common complaint we heard: scores of traffic signals that drivers think are out of sync, making their already-difficult daily commute harder.
The massive job of keeping all those traffic lights working falls on Frank Aira, chief of the Public Works and Waste Management Traffic Signals and Signs Division. In short, he’s the county’s traffic-light guru. Mr. Aira feels your pain. He told the Board that his wish for a liveable traffic flow is this:
“It would be that every day, Miami-Dade traffic would be like that first day after the last school lets out for summer vacation, when everyone marvels at how great the traffic flow was that day,” he said. A lovely thought, but . . .
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In a nutshell, the county’s automated traffic-light history is short. It began in the 1970s with the use of the Urban Traffic Control System, which was replaced in 2012 with the current system known as the Advanced Traffic Management System, or ATMS. The next phase of the ATMS will include video surveillance, traffic-volume data and real-time travel time reporting.
We’ve asked Mr. Aira to examine readers’ complaints about three specific intersections that kept coming up in the conversation: U.S. 1 and Southwest 27th Avenue; Southwest 127th Avenue and Kendall Drive; and Southwest 82nd Avenue, from 168 Street to 120 Street, where it meets U.S. 1. He’s anaylzing the data and will let us — and you — know. Before tackling reader’s questions, Mr. Aira offers a quick tutorial in the form of a Q&A:
How are traffic lights set? “Traffic signals are timed based on time of day and day of the week. A typical traffic signal may have 12 to 15 signal timing plans. The timing plans are created to address different traffic patterns that can occur at different times and on different days. So when drivers detect a problem, they should identify the time and day it occurs,” he said.
What’s the public’s biggest misconception? “That synchronization means all the signals in a main road should be green at the same time. Synchronization means that the platoon of vehicles traveling at the prevailing speed should receive the green light as they are approaching the intersection.”
How do you know a signal is malfunctioning? “The ATM system will report when there is an equipment malfunction. But these unique signal issues are not synchronization problems. Traffic signals appearing to be out of synchronization occurs when the traffic pattern for a corridor changes, prompting the need to have the traffic signals along the corridor re-timed.
Does that mean the lights are never out of sync, but that traffic is out of whack? We’ll get to the bottom of that, too.