The Green Light Wizard

It feels like this traffic light has been red for ages.

While you might not enjoy waiting at a red light, your waiting is not unnoticed. In the pavement, a metal wire detects your car stopped above it. The wire loop tells the intersection’s control box. The control box whispers it onto a phone line.

The message that you are waiting rides the phone line into the St. Petersburg Traffic Control Complex -- a 10,000-square-foot white cinderblock building where street signs are printed and malfunctioning street lights are dissected.

That information is combined with data from the city’s other 292 intersections, funneled into a server, then passes through a wall into the control room.

On the left of two dual 48-inch computer screens, a gray box tells Jon Stephenson you are waiting behind a red light. Soon, other boxes light up to show another car stopped behind you and more in other lanes.

Stephenson watches the ebb and flow of cars at the intersection of Ninth Avenue North and 16th Street. He’s seated at a table in the dark control room where eight different screens relay the activity of St. Petersburg’s traffic control systems.

When the public calls and complains about traffic at a particular intersection, he can watch live traffic movement and give out a green light. While he might not do it for you today, he would if there is a call from the police department or other special situation.

Usually, the system is only monitored to check for traffic lights that are not working. The computer compiles a list every 15 minutes -- and technicians are dispatched to perform repairs.

Stephenson’s business card reads, “Manager -- Signals, Signs and Markings, Department of Engineering, Stormwater and Transportation, City of St. Petersburg.”

Just call him “keeper of the green lights.”

After training as an electrician in the Navy, he found himself unemployed and started a 30-year career with St. Petersburg by repairing stoplights.

For the past two years, he's staffed the controls that determine how long people wait at each intersection. The traffic computer system keeps tallies of all the cars that pass across intersections or make left turns. Stephenson feeds the data into a software program that spits out timing recommendations.

How does he know whether the recommendations work? He holds up his car keys dangling off a plastic stoplight keychain. “Best timing tool I’ve got.”

Traffic control is a perennial controversy. Keith Crawford at the Florida Department of Transportation (FDOT) District Office in Tampa has his own qualms with the city’s traffic management. A former traffic engineer for Atlanta and Clearwater, he now oversees the state roads that pass through St. Petersburg.

Crawford says St. Petersburg isn’t as aggressive in controlling traffic as Clearwater, Pinellas County or Tampa. During a county-wide traffic planning project, he found that St. Petersburg did not actively monitor traffic volumes -- something he checked weekly during the 20 years he was a city engineer in Clearwater.

Stephenson says that when technicians are out in the field they will make a note of problems they see. Stephenson's department performs comprehensive maintenance on intersections annually -- down to the tightening of bolts and checking of burned-out lights. The rest of the time his work focuses on complaints and construction projects -- like installing new school crossing lights.

Crawford advocates using traffic response software -- a highly precise control of traffic light timing. It uses sensors in the pavement to count cars and change traffic light times based on volume. The software can adjust lights every five minutes -- although 15 is more common. Crawford says that weather, time of day and special events can dramatically change the effectiveness of light timings.

While St. Petersburg has this ability, it does not use it. Instead, traffic lights in St. Petersburg run on a “time clock” with schedules for peak and off peak traffic. This means that a red light will always have the same duration regardless of the numbers of cars on the roads. Traffic lights are synchronized as groups of lights. Crawford says this works well for the one-way streets downtown, but not for the rest of the city.

Stephenson defends his decision not to use traffic response software. He says it is not responsive enough to make timely changes to the traffic lights. He says the system can clear traffic better on its own. There are other factors the system cannot account for.

Take Tropicana Field. Stephenson says he spent a lot of time meticulously preparing traffic plans. However, he found that cops prefer the overtime that comes from putting the lights into flash mode and directing traffic manually.

Traffic response software requires more effort, too: sensors in the pavement must be maintained more carefully because the system relies on them for accurate traffic counts.

Nevertheless, St. Petersburg’s traffic system does allow for more immediate response at night. This is supposed to give drivers a green light if there aren’t any other cars at an intersection. At 6 a.m. the system reverts to fixed waiting times.

Controlling all this is a single black Dell Pentium III mini-tower. A second one stands by as a backup. The server is woven into the city’s intersections by a spider web of leased lines that adds up to a $17,000 monthly phone bill.

Computerization started in 1986 and ended in 1992. The mainframe was replaced with a personal computer last year.

In St. Petersburg, there are 2,247 top lights. There are 9,160 light bulbs guiding movement. And one Jon Stephenson keeping them in sync.