Tag Archives: St. George

UDOT projects honored at WASHTO meeting

State projects win in “Quality of Life”, “Under Budget” categories

BOISE, Idaho — Dedication and understanding of the impact state-controlled roads have on motorists in Utah was recognized today, as UDOT projects in Southern Utah and Northern Utah garnered two regional awards in the 2015 America’s Transportation Awards competition.

The announcement today was made at the 2015 Western Association of State Highway and Transportation Officials (WASHTO) annual meeting. UDOT projects were among eight that won in each of the competition’s three categories: Best Use of Innovation, Under Budget, and Quality of Life/Community Development.

UDOT’s Bluff Street at Southern Hills Parkway Interchange was recognized in the Quality of Life/Community Development category, which recognizes “a transportation project that has contributed to the general quality of life and economic development of local communities. These innovative projects better connect people to businesses, jobs, health care facilities, and recreational activities while encouraging a mix of transportation modes. ” With comfortable weather and access to many outdoor activities and destinations, the largest city in Region Four provides so much of what St. George and Washington County residents who value quality of life are looking for.

So many new residents have come to the area seeking this quality of life that existing transportation infrastructure has been over-taxed. Nearly 43,000 cars travel along Bluff Street (SR-18) each day, and another 13,700 go through Red Hills Parkway. The clash of rural vs. urban can best be seen here, where a state highway suddenly becomes a city road where many cyclists and runners converge to get to and around the natural preserve. It’s the meeting point four multi-use trail systems, and is included in the course of many major sporting events in the area. All of this activity in a traditionally constructed intersection places residents and visitors at risk.

This was how the intersection looked before the project

This was how the intersection looked before the project

In order to accommodate the current population as well as the expected growth through 2030, UDOT, the City of St. George and the Southern Utah Bike Alliance (SUBA) collaborated to reconfigure the intersection by creating a center exit interchange.

The center exit interchange creates a safer section of road, while also maintaining a steady flow of traffic. Highway travelers can continue on their way on the outside lanes, while those needing local access take the inside lanes to an intersection that allows east-west travel.

The construction team saved $4 million in construction costs by utilizing the natural topography of the area and building the project within natural grades.

The project after it was finished. Note the center offramp and bike trails

The project after it was finished. Note the center offramp and bike trails

The project also integrated bike/pedestrian paths into the design, with box culverts under SR-18 allowing for safer multimodal transportation under busy roadways, thus connecting the community in a safe, efficient and positive way.

“UDOT should be commended for their positive design process that encourages outside voices and ideas,” said Craig Shanklin, SUBA President. “This was a great example of how the community can be involved in the design process and lead to a better outcome for all users.”

The Diverging Diamond Interchange at Brigham City’s US-91/1100 South location was honored in the “Under Budget” category. That category honors “a project demonstrating transportation efficiency while promoting economic and fiscal responsibility. The award recognizes a successful project brought in under budget that provided the greatest cost savings to the state(s) while offering maximum performance.”

How do you move a steadily increasing traffic flow through an aging, small interchange at the connection of US-91 and Interstate 15, near the northern Utah city of Brigham City?  With more than 20,000 vehicles a day — many of them trucks — originating throughout the region, this old, inefficient interchange was reducing the economic lifeblood of local communities to a trickle.

The new DDI at Brigham City on the day it opened.

The new DDI at Brigham City on the day it opened.

The 40-year-old interchange would frequently clog when vehicles at its ramps tried to enter the traffic flow.  The predominant west to south-bound traffic on US-91 was so steady during the day that it was nearly hopeless for other movements to occur.  This prompted risk-taking by trapped motorists at the ramps – and frequent crashes when they did.  Regional special events, like local university football games, would bring traffic to a complete halt.

UDOT traffic planners needed a solution, but the answer was elusive.  Soils adjacent to the Great Salt Lake were saturated by surface groundwater, making the interchange increasingly unstable.  Engineers wondered how to upgrade it without a massive redesign to accommodate the increasing pounding from trucks.  Similar rebuilds had cost upwards of $100 million – prohibitive under state budgets at the time.

The answer: innovate.  Engineers used an innovation to solve the water issue — geofoam — which allowed the new interchange to “float” on soggy soils.  Another innovation — advanced bridge construction — replaced the interchange’s old bridge over I-15 while adding a completely new span in a little more than 10 months.  Finally, the innovative diverging diamond traffic pattern was added to the design to solve the problem of congestion and safety.

The white blocks are geofoam, which was used to construct the DDI in a environmentally- and structurally- sound way

The white blocks are geofoam, which was used to construct the DDI in a environmentally- and structurally- sound way

The result? An efficient interchange that allows all traffic movements to occur safely and congestion-free, and all for less than $14 million.

“What UDOT and the project team eventually chose to do was not only innovative, but a brilliant solution to an extremely difficult situation with many built-in constrictions,” said Bradley Humpherys, a Senior Transportation Project Manager for Stanley Consultants.

Utah’s two projects — along with projects in California, Colorado, Montana, New Mexico, North Dakota, and Texas — will compete against projects from other regions in the U.S. for a National Grand Prize, the People’s Choice Award and $10,000 prizes to be given by the winners to a transportation-related charity or scholarship program.

The top two national winners will be announced in September at the AASHTO Annual Meeting in Chicago.

“These projects are a small sampling of the many ways in which state DOTs are improving peoples’ quality of life and providing for a vibrant economy,” said John Cox, American Association of State Highway and Transportation Officials President and Director of the Wyoming Department of Transportation.

The America’s Transportation Awards – co-sponsored by AASHTO, AAA and the US Chamber of Commerce – annually recognizes the best of America’s transportation projects in four regional competitions.  Learn more about the projects and the competition at: AmericasTransportationAwards.org

Nevada I-15 flooding required a multi-state response

A two-mile stretch of I-15 near milepost 91 in Nevada was washed away due to heavy rainfall that started on Monday, September 8th. In an unprecedented storm around 4 inches of rain fell in the space of 2 hours, flooding the road and washing away ground and asphalt leaving the interstate impassable. Record breaking numbers of rainfall were reported along streams in the area.

The Nevada DOT declared a state of emergency on Tuesday, September 9 due to the importance of passenger vehicle and commercial trucking flow on I-15. According to Arizona Department of Transportation, approximately 23,000 vehicles use I-15 each day between St. George, Utah and Las Vegas, Nevada.

Warnings on Utah’s freeway message boards were posted up and down I-15 letting drivers know that the freeway would be closed down and provided details for  alternate routes. These signs went as far east as Nebraska to provide enough time for travelers to change their routes.

Screen shot of tweet that says 'From nevadadot semi restriction lifted (except oversie w/o permit) on NV I-15Information was also available to drivers via the 511 phone line, the Utah Trucking Association, news outlets, Arizona and Nevada DOT’s, the UDOT Traffic website, the UDOT Traffic Twitter account and the UDOT Traffic app. UDOT’s social media channels proved very valuable during this event.

Travelers were directed to take S.R. 56 out of Cedar City to Nevada S.R. 319 and then to the U.S. 93 back to the freeway. UDOT and NDOT worked very hard to provide accurate and timely information to motorists traveling on this alternative.

State DOT’s had to work together. Although the closure was not in Utah UDOT was heavily involved in sending support to the affected areas. Due to increased traffic on S.R. 56 a UDOT Incident Management Team (IMT) was dispatched to assist. The IMT crews directed traffic, filled potholes and moved disabled semis out of traffic.

They also deployed a portable traffic camera trailer to the S.R. 18/S.R. 56 junction to monitor any potential problems and back-ups. UDOT’s Region 4 shared access to this camera with Nevada DOT. Region 4 was also able to respond quickly to a rockslide on the Arizona section of I-15 and sent snow plows to clear rock debris in the Virgin River Gorge area.

Southbound I-15 reopened to traffic on Friday, September 12th to one lane in each direction for passenger vehicles. Northbound lanes reopened on September 18.

Glenn Blackwelder a Traffic Operations Engineer at UDOT said “We could not have done it on our own. It took the communication and resources of the Traffic Operations Center, Region 4 and NDOT working together. We were pleased with how all agencies and divisions were able to work together to get I-15 back open as quickly as possible.”Screen shot of tweet and attached map showing detour route. The tweet reads "Reminder: Nevada I-15 closed due to flooding. So Cal and Vegas detour map:"

This guest post was written by Adam McMillan, Traffic Operations Center Intern.

Southern Parkway Project Uncovers Ancient Ruins

Note from the administrator: This post was written by guest writer Stephanie Fulton and UDOT Intern Sarah Stephenson. 

Pit House

Excavation units from early archaic or possible Paleoindian site.

The Southern Utah Parkway is a 33-mile project that will eventually become an eastern belt route for Washington County. Eight miles are complete from I-15 to the new St. George Airport. The third segment of the parkway is currently under construction at Washington Dam Road, where more than 15 archaeological sites have been found.


Archaeologists working on uncovering ancient Anasazi pit houses.

Crews have discovered prehistoric Native American ruins, one of which has been named one of the oldest sites investigated in Southwestern Utah. After significant research, scientists have discovered that the area has had continuous human habitation for up to 10,000 years.

UDOT has worked closely with local Native American tribes throughout the project. The Shivwits tribe, a native Utah tribe, was invited to the archaeological sites to search the ruins. They were also highly involved in the decision-making process regarding the preservation of the many ruins found.


Obsidian Lake Mojave and Bajada projectile points recovered from construction site.

Arrowheads, pottery, pit-houses and even prehistoric ruins including dinosaur fossils have been discovered throughout the project site and have been dated as far back as 400 B.C. During construction, 200-million-year-old fossils were also found, including the teeth from nine species, three of which could be new species. These were archived for future data and research.

Furthermore, UDOT has worked to protect threatened and endangered species throughout the project’s construction.

Overall the construction has gone fairly smoothly and the experiences during the archaeological findings have been incredibly valuable to UDOT as a whole. Dana Meier, project manager for UDOT, said, “We are an organization that learns,” which is what UDOT will continue to do throughout this project.

The project has received considerable public support because it allows for the future growth and expansion of St. George and its surrounding areas. Construction continues this spring and summer to extend the new highway another eight miles.

Photos were taken by Bighorn Archaeological Consultants, and Eric Hansen.