August 21st, 2012

BETTER JOINTS

1 Comment, Preserve Infrastructure, by Catherine Higgins.

Better longitudinal joints in asphalt pavement mean longer pavement life.

When not compacted adequately, longitudinal joints can be destined for failure and can threaten the whole pavement system.

A longitudinal joint in Hot Mix Asphalt pavement is formed when a new batch of asphalt is placed adjacent to existing pavement. Because of temperature and plasticity differences, sometimes the newer and older pavements fail to bond, and the joint has significantly less density than the rest of the pavement.

A long  joint that is not compacted adequately can be “the weak link in the pavement,” explains Kevin VanFrank, UDOT Engineer for Asphalt Materials. “What you have is a seam in the mat that’s difficult to keep water out of.” Because the joint is permeable, water seeps in, the pavement ravels and loses material. Soon that damage “starts to migrate into the balance of the system…you can lose the entire pavement system.”

Under the best of circumstances, joint is typically less compacted than the mat. Van Frank says that a small difference of two to three percent can be acceptable.

HMA mix designs also play a role in the compaction at the joint. “As we attack rutting, we end up with mats that are more difficult to compact and lose the compaction in the joints without making special effort.”

The best solution to achieving good compaction at the long joint is to use echelon pavement placement and install two widths of pavement at the same time. UDOT’s specification states that echelon paving is preferred; however, the method is not always practical because lane closures are required. When echelon paving is not practical, other techniques should be employed.

A survey of each of the fifty states conducted by the Federal Highway Association shows that long joint health is a big concern among departments of transportation. Half of the states were found to be not satisfied with the overall performance of long joints, however, not all states have specifications in place that seek to achieve good compaction.

Some states had density specifications in place and others defined accepted construction techniques. But, even though the survey found an array of best practices being employed, a definitive solution was not identified.

In an effort to find the best solution to achieve good joint compaction, UDOT will select projects and look to the paving industry to identify good construction techniques. “Our intention is to implement the compaction of the long joint to a standard value.”

“We’re going to define an outcome and let industry meet the outcome,” says VanFrank. “We have seen techniques used this year that make joint density approach mat density.” Van Frank believes that by using UDOT will select appropriate projects to be built next year and allow contractors to lead the way UDOT will be able to identify the best solutions to ensuring better joints.

August 16th, 2012

THANKS FOR THE MEMORIES

1 Comment, Optimize Mobility, Preserve Infrastructure, by Catherine Higgins.

To all those who sent in photos for the Faces in Transportation – Thanks!

Faces in Transportation is an annual competition that solicits photos that show the people who build, maintain and use our nation’s transportation system. UDOT employees sent in many great photos and two were selected by Director John Njord and Deputy Director Carlos Braceras.

Prizes of the contest include awards that go to the entering agency: first Prize, $500; People’s Choice Prize, $500; Three Prizes in each of three categories, $125 each.

Voting for the People’s Choice award is open. Follow this link to see UDOT’s photos and vote!


Created with Admarket’s flickrSLiDR.

August 15th, 2012

UAC AT UDOT

No Comments, Preserve Infrastructure, by Catherine Higgins.

AggieAir is a Utah State University service that uses small, unmanned aircraft to provide aerial images to a variety of customers, including UDOT.

Located at the Utah Water Research Laboratory,  the AggieAir  photo collection method was first developed in response to agricultural needs, specifically to evaluate the effectiveness of irrigation practices.

Aerial images for agricultural needs can also be met by using satellites or manned aircraft; both methods have limitations, however. Satellite images often have course resolution, cloud cover can obscure the view of the area being photographed and a delay of up to one month in acquiring images can make the information outdated. Manned aircraft services are expensive.

Small plane services, like AggieAir offer a flexible platform that can provide high quality images for a variety of needs quickly and easily. According to AggieAir Research Engineer Austin Johnson, “UAVs are popping up everywhere” for that reason. He visited UDOT recently and and gave an overview of AggieAir, including some UDOT projects that have use the service to acquire images.

AggieAir collects common RGB photos Near Infered as well as thermal imagery and uses software similar to GIS applications to process the image data. While in flight, the planes take photos about every four seconds. The images are then combined to make a Geo-rectified mosaic image of the ground surface and features. The cameras can also be mounted on a vehicle for gathering ground level images.

The planes are small, lightweight and launched into flight using a staked bungee cord. There is no landing gear, so touchdown can be bumpy. The planes are made of durable Styrofoam that can be taped up after a rough landing.

UDOT  has used the service to get aerial images of the Southern Parkway project and the wetland area near Utah Lake. Other possible applications for the platform include taking an inventory of freeway structures and signs, before and after construction images, cataloging historic occurrences of flood or wetland areas, tracking erosion on embankment slopes, identifying invasive plant species and evaluating treatment plans for eliminating those species.

August 14th, 2012

2013 MAP

No Comments, Optimize Mobility, by Catherine Higgins.

UDOT is collecting information for the 2013 Official Utah State Highway Map.

Lisa Holgreen, UDOT Communications Assistant sends out maps almost daily.

UDOT and the Utah Office of Tourism partner to produces the state’s Official State Highway Map, and the process to re-do the new map is underway. Updating the map takes into account input from UDOT employees, county road supervisors and state and federal agency representatives. Effort is underway now to contact people who may have suggestions for improving the new map.

While UDOT cartographers make the map’s features accurate, the Utah Office of Tourism makes it beautiful. Clarkson Creative, a local graphic arts company will design a layout for the new map that emphasizes Utah’s scenic attractions.

The map is used by citizens, visitors to the state and school children from across the nation who need information for school projects. Lisa Holgreen, UDOT Communications Assistant sends out maps almost daily. Every year, UDOT sends around six hundred maps to individuals and more to visitor centers across the state. If Holgreen gets a request from a visitor center, she can often send more than one thousand maps in a day. The Utah Office of Tourism also mails maps on request and distributes maps through visitor centers.

A digital version of the map is available online on UDOT’s website. To make suggestions for changes on the new map, email your comments to statemap@utah.gov.

August 13th, 2012

IC DEMO

1 Comment, Optimize Mobility, by Catherine Higgins.

UDOT recently hosted an FHWA demonstration of Intelligent Compaction.

Intelligent Compaction uses GPS to determine the location and number of passes and sensors to determine the temperature and stiffness of asphalt pavement. The technology may eventually take the guess-work out of compacting pavement.

US 89 and SR 180 in UDOT Region Three is the first of nine projects locations from across the country to employ and evaluate Intelligent Compaction. The data collected and experience gained by studying IC will eventually determine if the sophisticated construction method effectively takes the guess-work out of compacting asphalt pavement.

IC systems are similar to regular asphalt pavement compactors but equipped with GPS to determine the location and number of passes and sensors to determine the temperature and stiffness of the pavement. As the compactor makes passes over the newly installed asphalt, stiffness measurements are integrated with the GPS information on a display that gives the operator a comprehensive near real-time picture of the compaction process.

The system creates an animated, color-coded online map so the compaction process can be monitored. The animation can also be played back for review.

Although the process measures pavement stiffness, the intent of the project is to correlate stiffness with pavement density, which is critical when it comes to longevity of the pavement, explains Lee Gallivan, Asphalt Pavement Engineer with FHWA. “Compaction is really the central part of the performance of the pavement.”

“You can have a real great mix design that meets all the Superpave requirements,” explains Gallivan, but with poor compaction, the pavement will not achieve appropriate density and meet the test of time. Conversely, a poor or mediocre mix design can be compacted well, and that pavement may last a long time.  Extending the life of pavement “is where the public gets its money’s worth.”

Over the next two years, FHWA will sponsor IC demonstration projects in diverse parts of the country. The IC measurements will be correlated to nuclear gauge or coring density tests. The data collected from the geographically disparate projects will provide information about different mix designs, environments, substrates and traffic levels. Eventually, IC could become an accepted method for quality-control and quality-assurance for contractors and departments of transportation.

The Federal Highways Administration is sponsoring demonstrations of a new technology that uses radar to analyze pavement.

GPR technology uses radar to create a cross sectional analysis of the pavement.

The new technology can help determine the remaining service life of pavement without using invasive means. Testing is necessary to find out what conditions are causing pavement deterioration, and then to determine the right course of action to take to preserve or replace the pavement.

Typically, engineers determine the remaining service life pavement by drilling core samples. Coring pavement takes time and resources to extract , transport and then test the pavement. Coring is also an inconvenience for the traveling public since lane closures are required for the work to take place.

Ground Penetrating Radar can provide a close and detailed look at pavement without the time, expense lane closures required by coring.

GPR technology uses radar to create a cross sectional analysis of the pavement under the surface. The equipment is mounted on a regular vehicle that can move with traffic, so no lane closures are required. While coring gives snap-shot looks at pavement condition.

In one sweep, GPR can collect enough information to have a comprehensive view of the pavement, including density, material variation, degradation due to stripping or other factors, and thickness. The data collection method works on concrete or asphalt and is “a better way to diagnose the problem,” according to Tom Yu, Senior Pavement Design Engineer with FHWA.

Although GPR is a great diagnosis tool for pavements that need rehabilitation, Yu sees other opportunities as well. “For me, the most promising area is construction [quality and assurance] testing.” Yu visited UDOT Region Three recently with a GPR equipped van and spoke at an Intelligent Compaction Demonstration. He will take the van on the road to collect data so he can demonstrate the usefulness of the new technology. “It needs to show its own value” before the pavement data collection method is widely adopted.

August 9th, 2012

WAY TO GO, STEVE!

1 Comment, Preserve Infrastructure, by Catherine Higgins.

A UDOT Region Two employee received recognition from Governor Herbert for making a safety improvement.

Steve Poulsen

Some local motorcycle riders noticed some slick pavement on an on ramp and contacted UDOT Region Two engineer Steve Poulsen to ask for a remedy. His quick and effective action to improve safety got the governors attention. Poulsen was presented with a thank-you letter from the governor at a recent UDOT Senior Staff meeting.

Poulsen received a call from a motor cycle rider who uses the California Avenue on-ramp to southbound I-215 to go home from work each day.  “He, along with several of his friends ride motorcycles and they noticed a slippery condition on the onramp that concerned them because their motorcycles would slip as they entered the turning portion of the ramp,” according to Poulsen. The man went on to say he appreciates UDOT but had concerns about the potential safety hazard.

Poulsen asked motorcycle rider Ed Layton, a trainer at UDOT Region Two, to ride the ramp. “Ed verified back that it was a safety issue,” explains Poulsen.

The ramp was part of a recent improvement project, so Poulsen then contacted UDOT Resident Engineer Brian Chamberlain who oversaw construction on the project. Chamberlain suggested that the contractor take a look at the ramp surface. “The job was partial deck repair in various locations using a product that sets fast,” Poulsen explains. Poulsen and Chamberlain visited the site and confirmed that the patch area was slick and soft.

Project contractor Green’s Concrete came up with a solution. The surface of the pavement was reheated on-site and some rock was installed to provide additional friction. “And evidently it worked because I got feedback from Brian that once the stuff was re-heated with some topping rock, it set up much better.”

“It was nice to be recognized by John Njord, senior staff and the governor,” says Poulsen. He was surprised that the motorcycle rider took the time to contact the governor’s office. Poulsen is also grateful to Chamberlain, Layton and Green’s Concrete for their help.

August 8th, 2012

CONTROLLED SLIDE

No Comments, Uncategorized, by Catherine Higgins.

Crews unload parts of a new avalanche control system.

UDOT is installing new avalanche control systems that can be activated remotely.

Two of the new avalanche control systems are being installed in a known avalanche path called Valerie’s Slide in Little Cottonwood Canyon on the lower face of Mount Superior.

“It is unique in that it will allow us to initiate snow slides without artillery,” says Project Manager Steve Poulsen. The system is a better alternative than howitzer-fired or hand dropped shells since the slide area is adjacent to Snowbird Village and SR-210.

The visible part of the system is a downward-facing twelve foot long, two foot diameter tube. An underground oxygen and propane storage farm feeds the gases to exploders where the gases are mixed in preparation for firing. The units are then triggered by remote control producing a shock wave that moves through the tube. The resulting controlled slide prevents a bigger, potentially more destructive slide.

Two similar units have been in operation for two years. The new units are planned to be operable for this coming snow season. “Next year we plan to install 5 more units along other slide path starting zones in the Mt. Superior area that will further reduce the need to fire artillery over Snowbird village buildings,” says Poulsen.

August 7th, 2012

GOING GREEN

No Comments, Optimize Mobility, by Catherine Higgins.

A new tool will improve the way UDOT monitors and optimizes traffic signal performance.

UDOT is using a new online tool for automated traffic signal performance measures.

To keep traffic moving, traffic engineers aim to create signal timing plans that allow most cars to reach an intersection on a green light, according to UDOT Traffic Signal Operations Engineer Mark Taylor.

When cars reach the intersection on green, concerns such as waiting and frustration, traffic delay, pollution from idling and wear and tear on vehicles and pavement are all reduced. And the dilemma zone, the point at which drivers decide to stop or proceed through the signal, is also reduced, which improves the safety at intersections.

But establishing and maintaining efficient signal plans typically costs thousands of dollars to develop. Engineers use resources, including equipment or people to monitor signal operations, collect traffic volume counts and then model and create a signal plan, explains Taylor. Since collection and modeling methods are time and resource intensive, updating the signal plan is usually only done every few years.

Plus, typical modeling and collection methods only providing a limited, snap-shot view that degrades over time as traffic patterns change. To really improve signal operation, “we need to know in real time where the problems are so we can make corrections to operations to improve traffic flow,” says Taylor.

UDOT is using a new online tool, called Signal Performance Metrics, originally developed by Indiana Department of Transportation and Purdue University. The system uses Dilemma Zone radar detection already in place along with reconfigured software provided at no charge to UDOT by developers at Wavetronics and Econolite.

The system locates and counts cars, places a time stamp on every car and then pulls that data into online graphs that can be observed in real time. “We’ve got over 500 sites where we already have Dilemma Zone detectors installed at intersections,” says Taylor.

Signal Performance Metrics has a potential benefit for signal operation everywhere but especially on weekends when signals operate with plans designed for week day off-peak hours. Taylor says the system “will help us be much more proactive with traffic signal timing seven days, twenty four hours a day.”

UDOT Director John Njord has charged traffic engineers with creating a world-class traffic signal system and employing Signal Performance Metrics is a step in that direction. Taylor is pleased about the ability to see in real time whether existing signal plans are good or bad so signal timing can be changed as needed, without using limited funding to monitor corridors or intersections. He thinks the traveling public will eventually see better traffic progression and less delay. “This is big for us.”

August 3rd, 2012

LEND A HAND

No Comments, Uncategorized, by Catherine Higgins.

Local residents recently helped UDOT ‘hand paint’ a bridge.

A pedestrian bridge that will be put into use over U-111 at 8200 South is decorated with the bright colored hand prints.

A pedestrian bridge that will be put into use over U-111 at 8200 South is decorated with the bright colored hand prints. The unusual adornment method was proposed by State Representative Jim Bird.

UDOT embraced the idea and extended an invitation to the public to participate. Many of the people who lent a hand to the project will also benefit from the structure once it’s put in place.

“It turned out to be a really great event,” says Andrea Gumm, Public Information Manager on the project. Initially, people who live in the area were targeted for participation. After a story about the upcoming event appeared in the media, word got out –“we got people from all over.” About one hundred people responded.

Gumm sees the hand prints as a way that people can feel some ownership of the structure. Those who showed up to “leave their mark” were really enthusiastic. She observed several children pointing out their hand prints and stating that they would remember and show their prints to friends once the bridge is in place.

The pedestrian-bridge was removed as part of work done on 7800 South and Bangerter Highway. Since the bridge still has some functional life, the structure will be put to good use on U-111 at 8200 South, a location that has been identified as needing a safer pedestrian crossing.

The bridge will be moved into place this fall.