Lake County touts time, gas savings for drivers
You likely have seen the heavy equipment at work on a road project somewhere in Lake County, but far less obvious measures have been used to save motorists time and money.
The Lake County Division of Transportation for the first time is tooting its own horn, so to speak, on the value of coordinating traffic signals, tweaking their timing and technology enhancements.
According to traffic engineers, a 17-month study of signal timings along portions of Washington Street, and Old McHenry, Deerfield/Saunders, Aptakisic, Rollins and Delany roads showed adjustments saved commuters 1,625 hours in travel delays and nearly 545 gallons of fuel per day. Using a formula that combines various factors, the smoother traffic flow translated to a total cost savings of about $9.8 million for drivers.
"Sometimes, it's just a little bit of tweaking and sometimes it's wholesale changes," said Bill Eidson, traffic signal engineer for Lake County. "People don't realize the impact that making timing changes can have."
The $123,270 study conducted between September 2013 and February 2015 involved before and after observations along the six corridors during peak travel times in the morning, midday and evening. Changes in delays and fuel used were calculated using travel times, stops and average speed. For motorists, the daily results are small but cumulative.
"Sometimes, it's the difference between seeing the first pitch at a kid's baseball game and missing it," Eidson said.
The division of transportation used the example of someone driving south on Delany Road in the morning and north in the evening between Route 41 and Wadsworth Road.
After signal timing changes, travelers on that stretch saved about three minutes in the morning and 71 seconds in the afternoon. about 20 minutes each workweek, the study showed. Overall, that amounted to an annual benefit of $1.28 million.
The county has been on a road work tear each of the past three years, averaging about $123 million in new and carry-over projects. Lake County Board Chairman Aaron Lawlor acknowledged that sitting in summer constructing delays is no fun, so publicizing successes, such as the traffic signal timings, helps illustrate long-term benefits, he said.
"It's all about how we're articulating value to our residents through our road program. It's not always (about) new pavement," Lawlor said.
Jon Nelson, engineer of traffic for the division of transportation, said the travel improvements from the signal timing changes were expected and continue today, but the study results help to show a quantifiable benefit. Many agencies commission such studies, he added.
"We've been doing these kind of studies for years and we've done a poor job of telling people what we do," he said.
A traffic signal is considered to include all the lights at a given intersection. Lake County maintains 165 signals. Every one of them is timed for the location but not all are coordinated, Nelson said.
During off peak or early morning hours, or at some isolated intersections, the signal depends on how many vehicles are present at a given approach - if no cars approach, the light would stay red or green. In a coordinated system, the schedule of greens proceed in a set order, which is why one might wait at a side street when there is no traffic on the crossing street. Circumstances, such as an emergency vehicle passing through or a pedestrian crossing button being activated alter the normal cycle.
"The challenge we have is we can make the green light as long as we want, but how long is the person on the side street willing to wait," Nelson said.
Technology has become a more important part of the road program. Fiber optic cable, for example, allows for more and clearer images to be transmitted to the Lake County Passage traffic management system, which monitors signals and road conditions.
The division of transportation also is considered the first in Illinois to implement adaptive signal control technology, equipment that is able to make more sophisticated decisions of when to give a green light based on traffic flow. That became operational last fall on about a 4-mile stretch of Aptakisic Road between Route 83 in Lincolnshire and Route 21 in Long Grove.
"The technology is a piece of the whole process, but it's not the driving factor of seeing the (time and fuel use) improvements," Nelson said. "The timing aspect is the main key."