IDOT: Roundabout the best solution for crash-prone Sterling intersection

DIXON – Speed and an increasing volume of traffic are what’s behind a rise in crashes at a Sterling intersection, and the best way to slow things down and still keep traffic flowing is by installing a roundabout.

So say Illinois Department of Transportation District 2 engineers, three of whom are based in the Dixon office but live in Sterling and are quite familiar with the intersection of north-south-running state Route 40/Locust Street and east-west-running Science Ridge Road, just outside city limits on the north edge of town.

An increase in collisions there over the last 5 years has raised concerns for many who live in the area or travel through there regularly.

The last straw for staff at the District 2 office came on Oct. 26, when a teenage driver, eastbound on Science Ridge, pulled out in front of an oncoming northbound semi. His passenger, Natalie Williams, 15, a Morrison High School sophomore, died at the scene.

Sterling Township, which is responsible for Science Ridge Road, has since paid for the Lee County Highway Department to bring its equipment over and cut rumble strips on either side of the intersection as the road approaches Route 40. Flashing red lights were added to both stop signs. Both were meant to be a temporary fix.

Still, several crashes have happened there since.

The Illinois Department of Transportation is responsible for Route 40, which turns into Locust as it crosses into city limits.

“We became aware of the concerns and initiated [a study of the intersection] because we felt that it was definitely important to consider improvements we could make,” Becky Marruffo, IDOT engineer of project development and one of the Sterling residents, said at a virtual public hearing Thursday held to discuss possible safety solutions.

“We have a personal a well as a professional interest in seeing improvements to the intersection,” Marruffo said.

Before a roundabout can be installed – a process that takes about 3 years from initial study to construction – the engineers are recommending a temporary 4-way stop be constructed. it will put the brakes on big trucks and other traffic streaming through the area immediately, while a permanent solution can be arrived at.

At this point, though, everything is simply a preliminary proposal, with no agency approval or funding yet.

Money was not budgeted for any Route 40/Science Ridge work because it was not identified as an unsafe intersection and so included in the list of projects IDOT planned to tackle this year.

Since the intersection has come to their attention, though, the Dixon crew is seeking to get approval and money from IDOT’s Highway Safety Improvement Program.

District 2′s virtual public hearing, attended by 34 people is one of the first steps in the process.

Potential solutions presented Thursday included leaving things as they are now, installing four-way traffic lights, or installing a roundabout.

The intersection was reconstructed in 1993 and resurfaced in 2015. There’s a house slightly east of the northeast corner, otherwise, there are fields all around, with Wahl Clipper, Candlelight Inn, and other restaurants, businesses and car dealerships as you head south on 40 toward town. Residential areas are to the west and east of the intersection.

It’s essentially a wide open, rural crossroads, with a 55 mph speed limit on 40.

That speed, and the increase in traffic during Wahl Clipper shift changes, and school openings and closings, and from seasonal agricultural traffic, account at least in part for the increase in collisions.

A proposal for the temporary four-way stop signs, which will cost about $128,000, has been submitted and the Dixon engineers are hoping that approval will come and work can begin in the fall.

Environmental studies must be completed and cost estimates, including construction costs, right-of-way acquisitions, utility relocation and long-term maintenance of the project, must be firmed up before a proposal for the roundabout can be submitted. That entire process usually takes about 3 years, so the roundabout, if approved, wouldn’t be completed until 2024.

Crash points

Problems with the 30-year-old intersection are varied.

The crash report – a history IDOT keeps of its troublesome intersections – shows many collisions there involve people stopping at the stop sign then heading onto or through 40 and getting hit, either because the driver can’t see far enough up or down 40, or more likely, because the driver underestimates the speed of oncoming traffic.

Mike Keuhn is the studies and plans engineer.

“We noticed that at the intersection, while a driver cans see quite a ways sitting at the stop sign at Science Ridge Road, when there is a vehicle using the Illinois 40 right turn lane, it may obstruct the view of other approaching vehicles,” he said Thursday.

“Another possible issue is speeding on Illinois 40. Are the stopped cars thinking that the approaching Illinois 40 vehicles are going 55 mph when in actuality they’re going 65 mph?”

Their goals are to “reduce the conflicts that cause the angle crashes [T-bones], reduce the severity of the crashes, increase the sight distance, reduce obstructions at the right turn lane on Illinois 40 and then manage speeds, preventing Illinois 40 traffic from speeding or even possibly reducing speed,” Keuhn said.

A roundabout is the safest and most efficient way to meet all of those goals, the engineers said.

Over time, given the ongoing increase in traffic, waits at a four-way signal system only will get longer and longer, so that’s not a good solution. Plus, it wouldn’t solve the safety issue.

That’s because the majority of crashes occur at signalized intersections, and the severity of crashes are significantly worse when someone runs a red light, while roundabouts slow vehicles down to 20-24 mph and have fewer conflicts points (places where vehicles can collide, 32 for a typical intersection, eight in a roundabout), they said.

Splitter islands will slow traffic down as it approaches the roundabout, and its design also takes farm equipment, tractors, combines, semis – all kinds of large or oversized loads – into consideration, project manager Brad Cushman said.

Traffic doesn’t really back up at a roundabout, and they are less expensive, too – they save $5,000 to $10,000 a year on electricity and maintenance costs, and they last 25 years, signals only 10.

The city of Sterling spent about $1 million on its roundabout at Lynn Boulevard and LeFevre Road, which it needed to better accommodate higher volumes of traffic coming from Halo Branded Solutions and other growing companies in the Meadowlands Business Park.

The two are both single-lane roundabouts and markedly similar.

The LeFevre roundabout has been open about 6 months, and despite the fears of many who said crashes would increase as a result, the opposite, in fact, is true, with few, if any, reported in the new roundabout.

The city also has plans to improve traffic flow near the riverfront that include a roundabout at Avenue B.

The Dixon staff had a group of independent crash experts review their data and their plans before the informational meeting. They also still want to hear any questions or concerns people might have about the project, Marruffo said.

Contact Cushman at brad.cushman@illinois.gov or 815-284-5996.