Widening of Redwood Road Enhances Safety for Multiple Types of Transportation
Rapid Growth, Rapid Development: Utah DOT Widens Redwood Road to Keep Up with Population Increase in Saratoga Springs
Traffic is moving more safely and quickly since the Utah Department of Transportation (UDOT) widened Redwood Road in Saratoga Springs.
“Redwood Road is the only continuous north-south road that connects this area to counties to the north, so an improvement was important,” says Geoff Dupaix, Spokesperson for UDOT. “This is one of the fastest growing areas in our state.”
The Utah Governor’s Office of Economic Development reported Saratoga Springs experienced the fastest growth rate in the state from 2000 to 2010 at 1,672.8 percent. The state anticipates continued growth – as the current population is about 50,000 – and the city is expected to be home to 130,000 residents at build out. “The growth does not look like it is going to stop any time soon,” Dupaix says.
Although not adjacent to a major city, Saratoga Springs has available land and is within commuting distance to Salt Lake City, adds David Gill, Project Engineer with UDOT.
UDOT received federal funding for the $41 million project. The department hired Avenue Consultants of Taylorsville, Utah, to design the projects.
As the city developed, municipal officials collaborated with UDOT officials and pushed new development a distance from the road to avoid difficulties when widening occurred.
UDOT broke the project into two phases, so work could begin more quickly on at least a portion of the road, Dupaix says.
“We were able to start building the first phase, while we still had to purchase right-of-way and hire another contractor for a second phase,” Dupaix explains.
Granite Construction of Watsonville, California, completed the first phase of the project in 2018. It included increasing 1.5 miles of the two-lane road to five lanes, plus a multi-purpose trail for bicycles or runners. The project started at 400 South to Lake View Terrace Road. At Grandview Boulevard, the department added dual left-turn lanes. Most of the commercial development is in the first phase and residential in the second phase.
In 2018, contractor Geneva Rock of Murray, Utah, began the second phase on the project, which increases the width of the road to four lanes, plus the multi-purpose lane on the 2-mile stretch from Lake View Terrace Road to Village Parkway.
The department also installed an east-west Continuous Flow Intersection at Pioneer Crossing, a major east-west connector, and added traffic signals on Redwood Road. Initially, the department planned on two new signals, but by the time the projects were under way, traffic volume had increased enough to require four traffic signals. The project completed in fall 2019.
“Building these projects, while the city continues to grow, was a unique challenge,” Dupaix says. “We were able to react to the changing conditions with the new developments coming in and new schools coming in, but we kept traffic moving.”
Geneva Rock used equipment with machine guidance. Work, such as relocating underground utilities, continued during the winter months.
All travel lanes remained open during morning and afternoon commutes, with most of the work taking place overnight. Crews started widening to the outside, and when that was completed, the traffic shifted to the new roadway and work began on the other side.
“Maintenance of traffic was a key component to making this project successful,” Dupaix says.
Dupaix adds Geneva Rock was responsive to any concerns.
“That is one of the keys to having a successful project,” Dupaix says. “If we can work with our contractors and they realize the importance of working with the public, it allows us to better respond to concerns.”
A Continuous-Flow Intersection
A continuous-flow intersection (CFI), also referred to as a displaced left turn intersection, was one of the most interesting aspects of the second phase.
The at-grade intersection allows vehicles making a left turn from Pioneer Crossing to crossover before the intersection and then move forward onto north or south Redwood Road at the same time Pioneer Crossing traffic flows in the east or west direction.
“The continuous-flow intersection allows us to improve mobility and enhance safety for the drivers,” Dupaix reports. “It has more vehicle handling capacity than a standard intersection.”
UDOT has eight continuous-flow intersections currently in operation. This is the first one in this part of the state and only the second in Utah County. This type of intersection is, typically, less expensive to build than those with elevations and ramps.
“We had to widen and put in raised medians to control the traffic,” Gill says. “It was challenging putting the CFI together while maintaining the existing intersection.”
Another interesting challenge was the difficulty in changing the traditional signal over to the new CFI signal while maintaining traffic safely.
“To minimize traffic delays, we worked with UDOT to coordinate the work, so it would happen during a Saturday night into Sunday morning,” says Michael Summers, Project Manager for Geneva Rock. “The old intersection lighting system was removed, and the new signal system was installed, and the roadway re-striped in, literally, a 24-hour period. This took long hours and a lot of coordination between UDOT and our subcontractors to make this happen successfully. When the commuters returned on Monday morning, there was a completely new interchange.”
About 70,000 vehicles are driving through it daily. Dupaix reports that it took drivers a couple of weeks to adjust to the new configuration. The department added more signs and striping to help drivers understand how to get where they wanted to be going. Additionally, UDOT sent out educational materials before the intersection opened.
Active Transportation Elements
The new intersection incorporated two-stage left-turn boxes for bicycle riders. Cyclists will go into a designated area ahead of the stopped traffic. Then they move to the other side of the road with the vehicles. When that traffic stops, they will move with the cross traffic.
In this area, Saratoga Springs City has trails, which parallel both Redwood Road and Pioneer Crossing, and has an active cycling community. During the design phase, engineers worked with UDOT to include the bike box design so the trails and bike routes would be connected at the intersection.
“A few local cities have added bike boxes on their roads, but this is the first location where the department has implemented this type of feature in Utah,” Dupaix says. “It’s a reflection of trying to incorporate the active transportation elements.”
UDOT also added bike slip ramps, which provide an additional option for cyclists who would prefer to use the crosswalks to cross the intersection.
“We’re trying to use a unique feature to enhance safety for people who ride bikes as they interact with the motoring public,” Dupaix says.