JEFFERSON CITY, Mo. - Stopping at red lights cost Mid-Missouri drivers hundreds of thousands of dollars last year in fuel.
When ABC 17 News asked viewers what intersections in the area were most frustrating and why, most responses targeted several Columbia intersections.
But a couple Jefferson City intersections stood out as well - including along Missouri Boulevard and at West Truman Boulevard and Country Club Drive.
Missouri Department of Transportation Central District traffic engineer Trent Brooks met ABC 17 News at that intersection to again discuss how lights are timed across the capital city.
"We use a standard equation that looks at the speed people are driving, the speed limit basically, the distance they have to go and then we compute how much time that should take to change [the signal]," he said.
Like Columbia, most MoDOT-controlled intersections in Jefferson City are monitored using cameras that recognize when a car approaches the stopbar.
Still other intersections have loop sensors cut into the pavement.
But at West Truman and Country Club, the MoDOT-controlled signals are just yards from city-controlled signals.
"It's common that you'll have a state signal that's not that far away from a city signal and we just try to work together to make them work together," said Brooks.
ABC 17 News wanted to know how much time and money local drivers were spending sitting at signals.
In one report, AAA estimated drivers waste one-fourth of a gallon of fuel for every 15 minutes spent idling. If a driver idled that long five days a week, ABC 17 News calculated they spent about $225.55 a year, assuming gas prices were $3.47 per gallon (based on Jefferson City readings on ABC 17 Gas Tracker).
When ABC 17 News drove through the West Truman and Country Club intersection several times last week, we sat at red lights for an average of 30 seconds.
Using the previous assumptions and calculations, we figured our wait at the red light cost 30 cents.
Numbers from MoDOT show 29,000 vehicles pass through that intersection each day.
Assuming each of those vehicles was stopped for 30 seconds, the intersection at West Truman Boulevard and Country Club Drive would cost Mid-Missouri drivers $870 per day, or some $317,550 per year.
We asked MoDOT how fuel economy or emissions concerns played a role in signal placement or timing.
"We really just look at delay," Brooks said. "But to say specifically that the amount of fuel that's going to burned driving a decision on whether a signal is going to be put in or how to time a signal, it's more the delay side."
There is little definitive research widely used to determine environmental effects of traffic signals, as compared to other traffic management such as roundabouts or stop signs.
However, the Nevada Department of Transportation previously reported that roundabouts cut emissions by 30 percent.
The South Carolina Department of Health and Environmental Control previously reported burning one gallon of fuel produced 19 pounds of carbon dioxide. In our 15 minutes of idling, we would have produced more than four pounds.
More changes could come to Jefferson City intersections, Brooks told ABC 17 News.
Part of that is because of continued commercial development along Missouri Boulevard and on the city's west side.
"Together with [city planning departments], we'll ask for a traffic impact study so we'll know kind of what traffic they're going to generate and how it's going to affect the system," he said. "Ultimately, that developer will have to pay for improvements so it doesn't negatively impact the system."
Another reason for possible timing changes was extra traffic expected during work on Business 50 in Apache Flats.