By Craig W. Anderson
In a recent open meeting at Glenwood School, the San Joaquin County Public Works department revealed its plan to construct a roundabout at the intersection of Duncan and Comstock roads on the outskirts of Linden.
Why is the county proposing the construction of this instead of a traditional 4-way stop or signal-controlled intersection? That was perhaps the major question asked by the more than 40 attendees.
“The California Manual of Uniform Traffic Control Devices includes guidelines on when stop signs and signals can be installed,” said engineer Najee Zarif, one of the public works representatives attending the meeting. “This intersection fails to meet the thresholds to install an all-way stop or traffic signal.”
He also said roundabouts are designed to slow vehicle speeds by requiring them to approach the intersection at slower speeds which enhances safety and reduces collision rates.
“Farm Bureau understands what they’re trying to do: slow down traffic flow,” said SJFB President David Strecker. “If it’s just farm equipment or just cars and the usual trucking vehicles, those are OK. But mixing farm equipment and the hauling of it and cars is asking for traffic trouble.”
Molly Watkins, Linden farmer and consultant, commented, “This is impeding commerce in a production ag area. Basically, ag roads are a very different environment than auto-traveled roads.” She noted that the county is asking for more trouble by considering additional roundabouts at Hwy 4 and Jack Tone Road, and Hwy 26 and Jack Tone Road.
“This location is sure to create more congestion regarding cars and agriculture,” Strecker said. “Car drivers want to catch up and get going; ag vehicles such as tractors, harvesters, combines, scrapers and grain drills are heavy, slow to maneuver and they’re big, occupying a large part of the roadway.”
A disc and scraper is typically 18 feet wide, a grain drill is usually 20 feet wide and a typical combine harvester is 15 feet wide.
“They have to drive from field to field to get their work done and drivers in cars are usually frustrated by this,” Strecker said. “On the other hand I’ve received the one-finger salute for being behind the wheel of a large, lumbering, road-covering vehicle. I like folks showing me they think ag’s No. 1.”
County’s research/tough demonstration
The county conducted studies from July 2013 through June 2016 when the intersection had six property damage accidents, five injuries and no fatalities; from July 2016 to December 2020 the intersection experienced nine property damage incidents resulting in 11 injuries, none fatal.
A large video monitor ran a loop of animation during the gathering showing how the roundabout would work along with an aerial view of the 2018 demonstration/test of how agricultural vehicles would negotiate a roundabout with large traffic cones representing the borders. This took place at the intersection of Baker and Duncan roads on a large asphalt lot.
Some large vehicles had a difficult time with that roundabout template, crushing the diameter-defining traffic cones. This gave rise to doubts among those in the agriculturally-oriented gathering regarding the ability of the roundabout to handle large agricultural vehicles during harvest or any other time.
Meeting audience comments
As this was a minimally-structured open meeting, audience members were free to discuss the roundabout with the county representatives. Small groups of concerned farmers and citizens huddled with Public Works representatives and each other, discussing this latest version of what many said was a “build-it-because-we-have-the- money-to-do-so” project.
Some of the audience remained doubtful about the program’s usefulness: “This is being forced on us whether we like it or not and I don’t think a roundabout is needed here when other methods of traffic control would work. The accidents have happened with Comstock not having to stop at Duncan. Traffic control methods should have been tried first.”
“People just don’t obey traffic laws and ominous traffic patterns will be created by this roundabout as has happened elsewhere,” Watkins said.
Zarif said the roundabout proposed for the Comstock/Duncan intersection has been redesigned to accommodate any and all of the large, long and wide vehicles used by agriculture.
“We’ve encouraged open and continuous dialogue with the community to ensure that the proposed roundabout will be able to accommodate whatever size vehicles that will traverse the intersection,” he said. “The 2018 demonstration provided the county with valuable feedback that was used to adjust the design to handle the largest vehicles to use the intersection.”
Funding is provided by the Highway Safety Improvement Program (HSIP), a competitive program that determines funding eligibility via data-supported justification.
“The total cost of the project – $2.265 million – is 100% funded, and the funds cannot be used for any other purposes,” Zarif said.
Schedule for construction
Currently in the design phase, which should be finished in February, advertising for the construction contract will lead to the beginning of construction in the spring of next year. It is estimated to require four months to complete and construction will be staged to accommodate any harvesting operations with traffic routed around and through the roundabout, according to Sommer. “Public works will coordinate with the community in a pre-construction meeting to ensure that the impact of the construction activities are minimized,” Zarif said.
The one-lane rural roundabout features splitter islands to slow approaching vehicles and a center island with a wide truck apron for use by extra-large vehicles and equipment.
Roundabout’s adverse impacts
“The roundabout would be bordered on all sides by walnut and cherry orchards,” Watkins said. “We’ll get an idea of how active ag operations and farming equipment interact-or not-with the roundabout early in its construction.” She also pointed out that equipment drivers “aren’t necessarily good drivers” as drivers education courses have fallen by the wayside over the years.
“The roundabout’s supposed to be ‘traffic calming’” she said. “There will be accidents regardless of the roundabout’s presence.”
“Car drivers get anxious to pass when they’re behind a slow moving farm implement,” Strecker said. “This happens all the time with ag equipment on local roads. And they can’t see why you may be slowing, what you’re attempting to avoid and they’ll pass into danger.”
Benefits or not, the roundabout experience hasn’t always been terrific when they’ve been constructed. A few examples from Watkins, who said, “Many other roundabouts haven’t fared well. For example, Hwy 12 & Hwy 115 at Rio Vista required major modifications, Tracy’s roundabout on 11th Street needs serious work and the Escalon Bellota Road and River Road roundabout was removed and replaced with a stop light.”
She said the people in the room knew about these problems but the public works representative “didn’t want to talk about these failures. This is a major ag production area and these failed or heavily compromised roundabouts make it evident they wouldn’t work well in this ag production area.”
Strecker added, “The roundabout at Hwy 88 and Liberty Road is a tight, hard turn for farm equipment. It’s not comfortable at all.”