Category Archives: Preserve Infrastructure

CLIMBING BLACK RIDGE

A recently completed freeway project in Washington County has provided important travel and safety improvements for road users who drive the mountainous region.

Between the Black Ridge Mountains north of St. George to the Iron County line, I-15 is characterized by steep climbs and wildlife crossing the freeway. The important commerce and recreation corridor carries UDOT Region Four’s highest traffic volume with 25,000 vehicles a day, including 5,000 trucks, moving in both directions. A project to build new climbing lanes and install extensive wildlife fencing reached substantial completion in late September and UDOT has already received some positive feedback on the improvements.

Utah State Troopers noticed better traffic mobility right away, and called to tell UDOT Station Supervisor Todd Abbott. “They think it’s far out.” Abbot has been in touch with Point of Entry workers too, who indicate that local and interstate freight carriers are happy about the new lane too.

Black Ridge -- with only two lanes, road users experienced delay during peak travel times.

All road users are inconvenienced by travel delay, which also has an associated cost. But the extra lane offers the most noticeable benefit to passenger vehicles – “what an improvement, to get up the mountain from St. George to Cedar and not get behind two semis,” says UDOT Project Manager Scott Goodwin. Before the project, traffic on the two lane-north bound side of I-15 could be sluggish during peak travel times.

Goodwin managed Region Four’s first Design Build with the Black Ridge project. Anticipating the new lane would be built on the outside of the freeway, Goodwin was surprised when the contractor proposed building the entire project in the median. “It required more help from geo-tech – Jim Higbee was very involved,” says Goodwin. “It turned out to be a really nice project,” with the added lane and 12 feet of maintenance area between the mountain and new barrier. ATMS conduit and cable was installed through the project and south of the project, in an area improved two years ago.

UDOT works with the Utah Division of Wildlife Resources to identify appropriate improvements that work for wildlife.  Bruce Bonebreak, UDWR Habitat Manager appreciates the efforts to make interchanges, box culverts and other freeway areas more wildlife friendly. “This deer herd has suffered a lot in recent years from highway mortality when they try to access the winter ranges,” says Bonebreak. UDOT “has done a very commendable job” of working with UDWR.

Wildlife fencing was installed along both sides of I-15 from the lower part of the Black Ridge to the overpass west of Kanarraville, providing protection for over 12 miles of freeway. “This area has long been plagued with high numbers of collisions between vehicles and deer, particularly during the late fall to early spring period,” according to Randall Taylor, UDOT Resident Engineer. “At freeway speeds collisions are serious. Car parts and the carnage of deer carcasses along I-15 resulted in pleas for help from local residents.”

I-15 adjoins 2500 acres of land owned by the Indian Peaks and Cedar Bands of the Paiute Indian Tribe of Utah, and the Tribe also has an interest in reducing wildlife-vehicle collisions. Tribal efforts include improving plant life on the east side of the freeway to provide food for animals so hopefully, fewer try to cross. “If we can improve habitat on the east side of the freeway, it will not only save deer and elk, but also people,” says Gaylord Robb with the tribal office. Robb has secured a grant from the U.S. Fish and Wildlife Service that will provide additional fencing with an upcoming UDOT project.

The Black Ridge to Iron County project is the most in an ongoing effort to improve safety and traffic mobility on I-15 from the Arizona State line through Utah. Project Manager Scott Goodwin talks about taking on UDOT Region Four’s first Design Build with this project in a previous post.

ENGINEERING SPECIALTIES AT UDOT

Materials engineer John Butterfield discusses concrete pavement with workers on the I-15 Corridor Expansion Project.

UDOT Engineers from many different areas of expertise work together at improve our transportation system.

Most engineers at UDOT are civil engineers. Civil engineering is a designation for professionals who design, build and maintain structures in the natural and built environment.

Some common activities of all engineers include preparing reports and cost estimates, writing specifications and collaborating with engineers of other specialties. Within civil engineering, there are many specialties. At UDOT, most engineers fall into these categories:

Construction: Build and maintain roads and associated structures. Manage a team of engineers and technicians to inspect the work of contractors, monitor progress and pay bills.

Design: Design new roads or improvements to existing roads. Road features can include barrier types, curb, gutter, sidewalk, striping and sign layout, Coordinate with other design engineers for bridges, drainage systems, etc.

Geo-technical: Analyze and evaluate the natural environment to provide systems that support built structures associated with the transportation system. Design footings and foundations for bridges, design landslide mitigation, determine processes to prevent or mitigate settlement of roadway embankment or structures such as mechanically stabilized walls, retaining walls, bridges etc.

Hydraulics: Determine bridge length and geometry over rivers by analyzing the stream flows and taking into account potential events like storms; design roadway drainage systems.

Materials: Analyze and test materials, mainly concrete and asphalt used to build road surfaces, and determine the strength properties and insure to insure durability.

Project: Manage project budget, schedule and scope from design through construction.

Structural: Design, modify and maintain roadway structures such as bridges, box culverts and retaining walls. Perform inspections of bridges and propose projects to improve stability or to fix structures to meet new demands, such as increased traffic.

Traffic:  Analyze traffic movement using computer simulations to see how freeways and intersections function under different conditions such as changing traffic volume, road width or signal time. Determine the timing of new signals and make changes and improvements to existing signal timing to improve safety or mobility.

PMOSA MIX DESIGN

A Utah product could be the answer to more durable asphalt roads.

SR-121 near MP 29

Three thirty year old roads in Utah are aging remarkably well. While other asphalt roads in the area have been rebuilt, Randlett Road, the Bonanza Highway and SR-121, between Maeser to Lapoint near Vernal, Utah, show minimal wear and very few ruts and cracks compared to other roads that carry similar loads. What’s the difference? Pavement made from native asphalt excavated in Utah.

“It’s pretty stout,” says UDOT Engineer for Asphalt Materials Kevin VanFrank who has tested oil sands pavement with a Hamburg asphalt mix performance tester. After over 12,000 passes with the machine’s weighted wheel, the old pavement showed similar wear as compared to newer typical asphalt mix designs used on similar roads.

Old oil sands mix designs varied in the past. SR-121, Maeser to LaPoint was paved in road mix method using kerosene as a cutter to mobilize the oil sands. Randlett Highway and the Bonanza Highway were paved using a hot mix. To make use of oil sands today requires a standardized design that considers repeatability and durability.

Standardized design

Core sample of asphalt pavement made from oil sands

Oil sands, mined in the Uintah basin, are a source of natural asphalt that have been used in pavement for 80 years, explains Kimball Young, who is overseeing a project to put the product to work for the Uintah Transportation Special Service District with support from USTAR. Young’s project team has developed a non-proprietary design and placed oil sand pavement in test areas in Uintah County. Plant Mixed Oil Sands Asphalt uses un-processed oil sands along with the usual pavement components – crushed aggregate and hydrated lime.

The mix development process started with testing the old pavement. VanFrank worked with University of Utah researcher Pedro Romero on initial testing. Young worked with Tim Biel of CME Transportation group to continue the testing and development of a mix design that produces a stable mix and can be reproduced. Romero has maintained his involvement throughout the process.

All testing showed that pavement made from oil sands can produce high quality, durable pavement for light to medium traffic loads. The durability of oil sand pavement may be due to slower oxidation rates in natural asphalt as compared to asphalt from refined petroleum, explains Biel.

The mix design developed by Young’s team is composed of 35 to 40 percent oil sand containing  a minimum of 12 percent asphalt and 60 to 65 percent course aggregate. Young’s team is testing warm mix designs with and without hydrated lime.

SMOOTH ROADS

A Smoother Road Could Lead to Energy Savings and Increased Safety

A road near Arches National Park.

This guest post is provided by Andrew Johnson, former employee of the UDOT Traffic Operations Center.  

The rising gas prices have had an effect on all of us, one way or another, and without any relief in sight, many of us are looking for ways to save money and improve fuel efficiency. When we think about ways to improve mileage and save money, the factors that usually come to mind involve aerodynamics, engine efficiency, and tire pressure, but recent studies suggest that there is at least one external element that could impact both safety and energy savings.

Dr. Richard Willis, an assistant research professor at Auburn University, reported that some simple improvements to the smoothness of road pavement could save a lot of money. He suggests that, in total, we could save 2.4 billion gallons of gasoline and 900 million gallons of diesel every year, which would lead to an estimated $12.5 billion.

The problem is from something called rolling resistance, which can be defined as the energy that is lost between the tire and road. The imperfections in the pavement, as well as the stiffness of the tires, directly affects how energy is lost and how much is required to keep the vehicle in motion. Of course, it shouldn’t come as a real surprise that the less time we spend bouncing around on roads and highways, the more efficiently our vehicles will run.

Understanding the Numbers

The numbers for the above study were broken down like this: In 2010 a study by Schmidt and Ullidtz showed that slight improvements in road smoothness could yield reductions in fuel consumption by 1.8 to 2.7%. Some other studies have actually suggested that this number could be much higher – as much as 4.5%. The Bureau of Transportation Statistics, on the other hand, says that vehicles consumed 168 billion gallons of gasoline and diesel, which means that at an average price (according to AAA) of $3.66 per gallon ($3.93 for diesel) and a conservative estimate of 2% fuel reduction, we arrive at the $12.5 billion figure.

Driver Safety

The National Highway Traffic Safety Administration says that one third of all highway fatalities can be attributed to poor road conditions. Perhaps a little surprising is that most of these fatalities happen on two-lane, while the highways are comparatively safe. The combination of better road quality and better conditions (better visibility, wider lanes, etc.), actually seems to be more conducive to safe driving.

Utah’s Road Conditions

So how well has Utah done with providing smooth roads? According to the Federal Highway Administration – pretty good. The FHA released some statistics in 2008 that put Utah near the top for maintaining good roads. Of Utah’s roads, only 6.4% were considered to be in poor or mediocre condition, which is pretty good compared to states like New Jersey or Hawaii (48.6% and 44.4% of their roads, respectively, were considered to be in poor or mediocre shape).

More and more studies are showing us exactly how important it is to maintain our roads and look for ways to improve driving conditions. While there is a lot of internal factors that affect driver safety and energy usage (from engine efficiency to simply being a conscientious driver), a smoother road can have more impact than many of us think.

Image and information provided by Online Driving University and the National Highway Traffic Safety Administration.

References:

American Road and Transportation Builders Association, FAQs

National Asphalt Pavement Association, Press Release

 

MATURITY MATTERS

Determining the strength of concrete is critical when it comes to getting traffic back on the road.

A concrete cylinder is checked for compressive strength.

Concrete pavement starts out looking like a muddy jumble of rocks and dirt. The mix contains water, cement, aggregate, fly ash and additives. When combined, a chemical reaction occurs, and concrete matures as water hydrates the cement. It’s the job of UDOT engineers, contractors, transportation technicians and lab workers to verify when the compressive strength of concrete has been reached so a road can be put in service or the next construction process can be started.

Determining the strength of concrete takes expertise, time and effort. Concrete can be damaged if the wrong assessment is made so before freeway traffic hits new pavement, or back fill is placed against a retaining wall, workers systematically test the concrete to make sure adequate strength is reached.

Traditionally, transportation technicians first take field measurements to check for consistency, air and content of the mix. Then, the concrete is poured into cylinders using the same mix used for the project. Cylinders are tested in pairs at set time intervals using a mechanized press that measures compressive strength.

The traditional testing method is time and labor intensive. Costs for the process can add up, especially if the predetermined testing interval falls on weekends or after normal work hours – technicians need to retrieve and transport the cylinders from the field to the lab and lab workers need to be on hand to run the test.

The UDOT Region One Materials Lab is using technology to predict compressive strength of concrete while saving up to eighty percent of testing costs.

A maturity meter and sensor

The method uses sensors placed in concrete and a maturity meter to measure time and temperature. The data, along with a math formula, can be used to chart a maturity curve specific to a concrete mix. The curve can be created using sample cylinders before the concrete is placed in the field. Or, meter readings can be done concurrent with construction. The maturity curve allows workers to predict when compressive strength is reached.

The cost for testing one batch of concrete multiple times using traditional methods can easily add up to a few hundred dollars. One sensor can be read multiple times and costs less than $50 for the same information.

“A maturity curve shows the progress of the chemical reaction,” says Scott Nussbaum, Region One Materials Engineer. “Using maturity meters helps reduce risk, save money and open to traffic as soon as possible.”

A maturity curve helps predict when compressive strength is reached.

TRUCK REPAIR

Summer is spent getting ready for winter at UDOT’s Heavy Equipment Shop.

Rust holes in the side of a truck bed are gone. After a few coats of orange paint, this truck will be ready for winter.

John Walker, UDOT Equipment Shop Supervisor calls the employees who repair heavy equipment “talented craftsmen.” The before and after photos of the truck show the results of their careful work. This truck will be painted, and then be ready to be put back in service before the first winter storm.

Holes in the side of this truck were repaired.

 

 

 

 

 

 

 

 

 

AIR QUALITY

Air quality as it relates to transportation is an important concern among citizens and policy makers in Utah’s metropolitan areas where population growth has placed an increased demand on our transportation system.  

A construction zone on Bangerter Highway

Utah is one of the fastest growing states in the nation.  Our transportation system will need to be made as efficient as possible to support that growth. Projects planned through year 2030 will improve mobility – will building those projects necessarily contribute to a decline in air quality?

UDOT works with other state agencies in “a continual consultation process to make sure we’re in compliance with federal air quality standards,” according to Elden Bingham, Air Quality Programs Coordinator for UDOT. Bingham participates in the compliance conformity process along with representatives from federal and state regulatory agencies and local Metropolitan Planning Organizations.

The federal government requires states to monitor and comply with National Ambient Air Quality Standards, and the Utah Division of Air Quality monitors air quality in Utah.  The EPA has designated six pollutants that are monitored by DAQ throughout the state – the pollutant of concern to transportation planners are ozone and its precursors hydrocarbons (HC) and nitrogen oxides (NOx), carbon monoxides (CO), and particulates (PM-10 or PM-2.5). These pollutants cannot exceed specified levels. When air quality does not meet federal standards, a non-attainment area can be designated. States with non-attainment areas are required to develop a Statewide Improvement Plan.

SIPs, which are approved by the federal government, must contain air quality goals and strategies to meet those goals. UDOT works with the DAQ to develop transportation strategies that meet the air quality improvement goals in the SIP. All transportation projects must conform to the SIP in order to receive federal funding.

Conformity to Utah SIP goals takes place on the regional and project level. Metropolitan Planning Agencies manage regional transportation conformity of projects on the Transportation Improvement Plan, a list of proposed projects. After modeling future traffic demand and determining the level of emissions expected to be produced, the MPOs issue an Air Quality Memorandum that confirms that the projects in the TIP won’t exceed goals of the SIP.

Project level conformity is the responsibility of sponsors, like UDOT, who build transportation projects.  Projects that receive federal funding or those that are regionally significant (including primary arterial roads, freeways or fixed guide-ways) must conform to goals in the SIP. On the project level,  sponsors conduct a Hot Spot Analysis to show that transportation projects don’t contribute adversely to the air quality in the area.

Planning studies done by the Wasatch Front Regional Council show that improved mobility can actually have a beneficial impact on local air quality. Idling and excessive stop and go traffic puts strain on automobile engines causing increased emissions. WFRC compared future transportation conditions in 2030 with and without planned projects. By eliminating traffic delay, vehicle emissions will be reduced by 285,000 vehicle hours per day – that equals 1.2 tons of the precursor pollutant nitrogen oxide.

Precursor pollutants contribute to the formation of other pollutants; nitrogen oxide produces ozone along with light and heat. Air quality standards are expected to be reconsidered in 2013.

Links:

Utah’s emissions inspection program and cleaner running cars have also helped improve air quality.

To learn more about air quality conformity, visit the Air Quality Planning page on the UDOT website.

UDOT’s TravelWise website suggests option for drivers who want to save energy and help roadways operate more efficiently.

The Hot Spot Manual gives project managers air quality analysis guidance.

WFRC has posted the 2012-2014 TIP and and Air Quality Memorandum.

The Federal Highways Administration produces a brochure that summarizes the air quality conformity process.
The Utah Division of Air Quality website shows current conditions.

The Utah Department of Environmental Quality lists tips for individuals:  What You Can Do.

Tribune story: Salt Lake City and County officials ask parents to cut back on idling.

BOUNCE BACKS

New guidance devices are popping up on the side of state roads.

Steel post delineators are difficult to repair and usually need to be replaced. The white delineator in the background has a post that rebounds, even after several vehicle hits.

Delineators are devices with retroreflectors that are installed along roadways to provide guidance to drivers at night and during other low visibility conditions. “On dark and stormy nights, sometimes all you can see are those delineators,” says Lynn Bernhard, Maintenance Methods Engineer for UDOT.  It’s important to keep the devices in good working condition, he explains.

Traditional post-mounted delineators, made of galvanized steel with attached retroreflectors, are ubiquitous in Utah.  The delineators are prone to frequent vehicle hits on some state roads, so up-keep can be a challenge. When a post is badly bent, workers sometimes try to use brute strength to put it upright again, but usually, the post needs to be replaced. A few types of flexible posts have been tried without good success – some tend to shatter when hit in cold weather.

In those high-hit areas, UDOT is transitioning to using a new type of post that can withstand nearly ten times as many vehicle hits as traditional steel posts. The new posts are made of durable recycled plastic with a joint at the base that allows the post to rebound after a vehicle hit.

State Route 68 north of Eureka served as one of the test areas for the new posts. The narrow stretch of road serves vehicles towing trailers heading to nearby the Little Sahara recreation area. With a total of about 300 posts, workers were replacing about 800 a year. Test results show that the new posts will save material and man hour costs over the long run, even at three-times the cost of steel posts. The new devices also improve work-place risk, since fewer service calls are required. The amount of waste requiring disposal is also reduced.

“I think they’re very worth while,” says Chad Allinson, Eureka Maintenance Station Supervisor. He is quick to thank Bernhard for helping obtain the new devices. Allinson has found that the posts usually rebound after a hit, but the ones that get pushed over are easier to fix than the steel post delineators.

Another high-hit area, Provo Canyon, will get the new posts soon. Check back next week to read about how the new delineators, along with several other safety measures will improve winter operations on the winding, high mountain road.

PRE-WAR BRIDGE SURVEY

Some Utah bridges built before World War II are eligible for inclusion in the National Register of Historic Places.

UDOT recently completed a survey of pre-war bridges. The survey report will be combined with a previous survey of post-war bridges completed last year to provide an important resource that UDOT project teams can use during environmental, planning, design and construction phases of transportation projects.  The complete report is on   UDOT’s website and will be available at the Lester Wire Library soon.

This bridge at the mouth of Little Cottonwood Canyon is recommended as eligible for inclusion on the National Register of Historic Places based on its rare type and artistic value. See images of the other bridges below.

Along with an inventory of bridges and their features and locations, the report also includes a rich and interesting historical context.  Themes and trends in bridge design and roadway development “and how those trends were manifest in Utah,” is detailed in the report, explains Elizabeth Giraud, Architectural Historian at UDOT.  Examples of some pre-war themes include detailing how new technologies and materials were adopted into design and how federal legislation and economic conditions, like the Great Depression, affected the development of the transportation system.

Pre-war statewide priorities were promoted by the Utah State Road Commission, UDOT’s predecessor.  Formed in 1909, the USRC “focused on adding more grade separated roads, improving road surfaces, connecting to state boundaries and providing access to state scenic resources in the southern part of the state,” says Giraud.

The historical review draws on a variety of sources including Utah State Road Commission meeting notes and design manuals, planning studies, the UDOT bridge inspection inventory, historic state maps,  and the book that should always be within arm’s reach here at UDOT – Knowlton’s History of Highway Development in Utah. The historical background in the survey is really worth reading for anyone in the transportation industry. Knowing about past trends and innovations can foster a better understanding of present construction and design.

A detailed inventory form for each bridge was completed during the survey process. Inventory forms list bridge location and UDOT Region, dimensions, distinctive features such as variation on a given bridge type, and whether or not the bridge qualifies for inclusion on the National Register of Historic Places.

The bridges were determined to be NRHP eligible under criterion A and C of the rules for the National Register. To qualify under criterion A requires details about how the property functioned during an historic event or time period. To qualify under criterion C requires information about the distinctive type or aesthetic value of the property.  Bridges that are “works of the master” also qualify under criterion C.

UDOT will now partner with the Utah State Historic Preservation Office to establish a programmatic agreement concerning the findings. Eventually, the information can be added to the in the bridge so it can be easily accessed.

Facts:

  • 210 Pre war bridges were surveyed, 42 were determined to be eligible for the National Register of Historic Places
  • 409 Post war bridges were surveyed, 34 were determined to be eligible for the National Register of Historic Places
  • Only non-interstate UDOT bridges were inventoried
  • No bridges built prior to 1909 were found
  • Elizabeth Giraud is the Project Manager for the study which was conducted by Mead and Hunt.

The slideshow below shows some of the bridges that were identified by Mead and Hunt as eligible for the NRHP. Click on the large images to see captions.


Created with Admarket’s flickrSLiDR.

BLING FOR ROADS

UDOT is looking for ways to improve the visibility of pavement markings at night during rain storms.

Small glass beads applied to paint make pavement markings shine at night. As vehicle headlights illuminate the road, each bead acts as a tiny retro-reflector that bounces light back to the source. Collectively, the beads make pavement markings highly visible for drivers. That is, until rain covers the road, creating a shiny surface that interferes with the retro-reflective quality of the beads.

A double drop system applies paint and two different bead types.

Maintenance Planning Engineer Ken Berg and Region 2 Pavement Marking Coordinator Dan Betts are testing three different wet-night beads to see which one is the best retro-reflector. The test is a follow-up to work Betts has done to improve wet-night visibility and durability of pavement markings.

Betts’ method uses two different bead types – UDOT’s standard plain bead and a wet-reflective bead applied in equal proportion. Both are retro-reflective above and under water, but the wet-reflective bead is larger and has a “higher reflective index,” says Betts, making it better at reflecting light through water. Using two bead types “gives us the best of both worlds,” with good dry and wet retro-reflectivity.

To improve durability, the markings are placed in grooved pavement. Grooving the pavement slightly, about the thickness of a quarter, keeps the lane markings from being scraped off by snowplows and significantly improves life of the markings by six to eight times.

Soon, Berg and Betts will test three wet-reflective beads, all with different compositions, to see which one performs best during storms at night. Testing will be conducted on three contiguous 3500 foot sections on eastbound Bangerter Highway (SR 154) between Redwood Road and I-15. The close proximity of the test areas provides “a good comparison under similar if not exact conditions,” says Berg.

Pavement markings for the test were placed last week. On each test section, a different wet-night bead was applied in equal proportion with UDOT’s standard bead. All markings were applied on grooved pavement using the same method.

Next step: data collection

Both subjective and objective data will be collected. During storms, Berg or Betts will drive the sections, video tape and record field notes about any observable, subjective differences among the test sections. Collecting objective data is a two-person operation. A van with an attached retroreflectometer will be used to measure and quantify the reflectivity of the markings. Data sent to a lap-top inside the van will let testers see and compare measurements immediately.

The retroreflectometer measures by scanning across the marking, taking in some pavement on either side. A variety of information is produced, including a graph that provides a quick visual interpretation of the measurements. The software integrated with the retroreflectometer allows the user to choose from a variety of collection options. For example, upper and lower retro-reflectivity threshold values can be set for a pass-fail test.

By fall of this year, Berg and Betts expect to have preliminary results to share with others at UDOT and the larger transportation community. Testing will continue for two to three years, and the results will be used to select a cost effective safety improvement for road users.

More about UDOT’s pavement marking operations:

  • The retroreflectometer measures light in millicandelas per lux per meter squared.
  • Markings are applied using a double drop system that allows two types of beads to be dropped simultaneously on newly applied paint.
  • For maintenance operations, UDOT uses water-based paint for pavement markings, which is 5 to 10 percent the cost of durable pavement markings, such as tape. Recessing the paint stripes below the surface of the pavement can help the markings last up to eight times longer than surface applied paint.
  • UDOT Maintenance technitions can operate the pavement marking equipment, which saves time and conserves funding.