December 14th, 2011

BEAM ME UP

No Comments, Optimize Mobility, Preserve Infrastructure, by Catherine Higgins.

An innovative beam design promises strength and long service life for bridges.  

A new beam that uses Fiber Reinforced Polymer, a material that is rust resistant and stronger than steel may help bridges last up to 100 years.

Conventional steel-reinforced concrete bridge girders have a useful life of about 75 years, depending on traffic loads and weather. Seemingly impervious to the elements, “concrete itself is a giant sponge,” explains Mike Zicko, an engineer with HCB Company. Water, along with impurities from the roadway or deicing chemicals, is pulled in by the concrete and failure of bridges, whether it’s the deck, girders or other components is caused in most cases “by rusting of whatever metal is in the bridge.”

Rust causes the steel to expand and crack the concrete – protect the steel from moisture and the life of the structure is prolonged.

The second reason for structural failure of bridges is fatigue. “When something goes over a bridge, it takes away some of its life,” says Zicko.  After a lifetime of bending under the weight of traffic, steel can wear out.

A new beam that uses Fiber Reinforced Polymer, a material that Zicko says is “virtually impervious to moisture” and stronger than steel may help bridges last up to 100 years. FRP is seeing increased use in the transportation and other industries partly because it does not rust. UDOT has recently used FRP to reinforce the deck of the Beaver Creek Bridge and FRP bars are being used to extend the life of concrete pavement on I-15.

Called a Hybrid Composite Beam, the design uses an FRP box to protect concrete used in the beam from moisture. What’s inside the box is innovative as well; a concrete arch gives the beam compressive strength.

More than just a covering, the box “provides shear strength and encapsulates the tension and compression elements,” according to the HCB Company website. The arch structure inside the beam is surrounded with low density foam core. A prestressing strand provides additional strength and steel shear connectors provide stiffness. Along with being very strong and durable, the beams are also light and easy to lift and place.

The beam was designed by structural engineer John Hillman, President and CEO of HCB Company. UDOT will use the beam on a bridge near Beaver, Utah. A grant from Highways for Life  will provide funding to use HCBs on the project. HFL encourages state DOTs to use innovation to build a longer lasting transportation system.

December 13th, 2011

ASPHALT TRENDS

1 Comment, Preserve Infrastructure, by Catherine Higgins.

A number of trends in the asphalt pavement industry save money and use less energy.

New asphalt pavement in Washington City, Utah. UDOT's contractor used Hot mix asphalt containing recycled asphalt pavement or RAP.

Sometimes people outside of the transportation industry view pavement as a one-time use of resources. However, many of the products used for pavement can be reused or mixed in ways that use less energy. Asphalt and concrete pavement, for example, can be recycled. This article summarizes some ways asphalt pavement can be re-used or mixed using less energy.

RAP

Recycled Asphalt Pavement, old asphalt pavement that has been milled off or otherwise removed from a road or other installation, can be added to new asphalt pavement at a batch plant. In general, state DOTs allow more RAP in base courses than they do in surface courses. For example, the I-15 CORE project uses a multi-layer pavement design. The asphalt portion on the interstate uses thirty percent RAP but the surface streets use a smaller percentage of RAP.

According to Michael Kvatch, Executive Director of the Asphalt Pavement Alliance, tests show that high RAP content pavement on surface streets (10 to 25 percent RAP) can be “just as good, if not better than its virgin counterpart.”

CIR

Cold In-Place Recycling is a way to reuse asphalt on site using a long train of equipment. The process involves removing and pulverizing old asphalt, adding binder, spreading, grading and compacting the asphalt. CIR can be used to rejuvenate an old road or as a base course for new pavement. New aggregate can also be added during the process if needed.

CIR offers the advantage of being about one-third of the cost of new asphalt. CIR is a cold process, so the energy used to heat Hot Mix Asphalt is also saved. There are also many CIR processes and uses, which gives contractors and engineers at UDOT options for bidding and designing good solutions for maintaining roads.

However, regular Hot Mix Asphalt made according to a Superpave process is much stronger than CIR, so for high volume roads or cold climates, CIR may not be appropriate.

HMA is also more predictable than CIR, which is subject to many variables, such as original mix design and aggregate size, explains Kevin Van Frank, UDOT’s Engineer for Asphalt Materials. CIR is subject to many variables, including binder and aggregate type and size. Those variables make the characteristics of the final product a challenge to predict, especially when it comes to curing time. Because of the economic advantage of CIR, UDOT Research is funding testing that will establish standards for CIR.

Maintenance of Traffic is also a problem with CIR since the process requires a long train of machines that can stop traffic. UDOT places a premium on keeping traffic moving during construction, so CIR is not used in high traffic urban areas.

Sometimes people outside of the transportation industry view pavement as a one-time use of resources. However, many of the products used for pavement can be reused or mixed in ways that use less energy. Asphalt and concrete pavement, for example, can be recycled.

WMA

Warm mix asphalt pavement is produced using less energy. Hot Mix Asphalt is heated to 310 to 350 degrees Fahrenheit; the temperature range for WMA is as much as sixty degrees lower. HMA uses heat to decrease the viscosity of the asphalt in order to be able to place and roll the pavement. WMA uses Zeolite, waxes, surfactants or water to compensate for using cooler temperatures during production.

Zeolite is a “mineral sponge,” that transports water into the asphalt binder. Waxes act as thermosets that increase viscosity above the liquid phase. Surfactants can be added to coat the aggregates to make the binder workable at lower temperatures. Water injected during the mixing process causes the asphalt binder to foam so it achieves the viscosity needed to place and compact the material at lower temperatures.

WMA can be placed in the cooler months of spring or fall, which potentially lengthens the construction season. And, cooler asphalt has a milder odor, which can be good for road users and especially for workers.

December 9th, 2011

BRIDGE SMARTS

No Comments, Preserve Infrastructure, by Catherine Higgins.

An ABC approach helped UDOT keep traffic moving during construction of the Telegraph Street Bridge.


Created with Admarket’s flickrSLiDR.

The monolithic poured bridge was still in good shape for a more than 70 year old structure. But the roadway on either side was wider, witch made the bridge a traffic choke-point. Building a twin bridge to add additional capacity would have been expensive – both to build and maintain through the life of the new bridge.

“Bridges are more expensive to maintain than roadway,” says Joshua Sletten, UDOT Structures Design Engineer. Per foot maintenance costs of roadway maintenance are a fraction of the costs of maintaining a bridge – especially a long structure like the old bridge. Hydrological studies showed that a smaller structure would also be adequate to accommodate a stream under the bridge. A UDOT in-house design called for a new smaller structure to be built under the bridge deck.

The new bridge, a giant arched culvert, was built using pre-formed concrete components that were assembled on site as traffic was maintained on the old bridge. After construction, fill was placed over the new structure and the road was realigned over the top. Crews then demolished the old bridge, and the built a new wider road with two lanes in each direction and a center median.

Covering the new structure also adds a maintenance advantage; the fill provides a protective buffer between traffic and the structure.

For more, read an earlier post about how UDOT partnered with stakeholders during construction.

December 8th, 2011

NEW MATH

1 Comment, Optimize Mobility, by Catherine Higgins.

UDOT uses ramp meters to keep freeway traffic on an even keel.

New software to calculates meter rates to help smooth out traffic flow on I-15.

UDOT has been using ramp meters to even out freeway traffic flow and improve safety for several years. Metering breaks up bottlenecks, smooths out surges and keeps traffic on an even keel. Without metering, freeway speeds would likely be much slower, and travel times would be less reliable. Metering also improves safety because stop-and-go driving behavior is reduced and platoons are broken up, and fewer side-swipe and rear-end collisions occur.

The present way of metering takes average traffic patterns into account. But, “traffic is never average,” explains John Haigwood, Traffic Engineer at the UDOT Traffic Operations Center. “We can’t account for all the variations.” The graph below  shows variations in traffic during the evening commute, with the black line showing the average.

Sometimes metering can be too restrictive or too free. Restrictive metering allows too few cars to access the freeway, and metering that is too free can fill freeway capacity quickly and cause flow to be sluggish.

Because of variations, sometimes metering can be too restrictive or too free. Restrictive metering allows too few cars to access the freeway, and vehicles may stack on the ramps and available freeway capacity may go unused. Metering that is too free can fill freeway capacity quickly and cause mainline freeway traffic flow to be sluggish.

A new, more responsive way to control metering rates is being tried on I-15 in Salt Lake County.  UDOT is using new sophisticated software  that “automatically adjusts to actual conditions,” says Haigwood. The system is being provided by Wasatch Front Regional Council Congestion Management and Air Quality funds.

Traffic sensors measure backing on the ramp, and traffic speeds at the merge point and downstream, and the software calculates meter rates. “The system uses data collected from traffic monitoring stations that are UDOT fiber network,” says Scott Stevenson, a Traffic Engineer who works with UDOT on the new system. “These existing stations provide the raw data that is used for the travel time signs, traffic flow maps and now, corridor responsive metering.”

Engineers at UDOT’s Traffic Operations Center “are seeing a lot of success,” says Robert Clayton, Director of the TOC. Clayton anticipates having real data soon to back up the observations. In the meantime, engineers are keeping close watch on the test sections to make sure correct parameters are being set so the software can work correctly.

It’s a balancing act, explains Stevenson. “We’re trying to maintain a better flow on the freeway by adjusting the ramps, and visa verse.” By balancing the metering rate of the ramps with the flow of traffic on the mainline freeway, road users can take full advantage of available capacity, backing on ramps can be minimized and the overall operation freeway system can be optimized.

December 7th, 2011

WE CAN WORK IT OUT

No Comments, Optimize Mobility, Preserve Infrastructure, by Catherine Higgins.

Partnering between UDOT and contractors is essential when it comes to finding solutions and providing the public with a good quality transportation product.

Complex road construction projects that occur on heavily traveled routes, especially those near business districts, are often subject to construction delay due to utility conflicts or unexpected but necessary changes in plans. UDOT works hand in hand with contractors to resolve construction issues so the project objectives can be met, stakeholders can be kept informed and the public can enjoy and improved transportation system as soon as possible.

The Monticello Main Street Project reconstructed a three mile section of US-191 and US-491 through the business district of Monticello, Utah.

A UDOT Region Four project in Monticello provides a great road map of how to partner for solutions. The Monticello Main Street Project reconstructed a three mile section of US-191 and US-491 through the business district of Monticello, Utah. The project scope included pulverizing or excavating the old pavement; compacting and grading the road base, and installing asphalt and concrete pavements; removing and replacing three miles of storm drain; installing a highway lighting system; relocating high voltage overhead power and upgrading traffic and pedestrian signals.

“On large partnered projects like this one, the issues that arise can start out small and quickly become worse if not addressed early,” says Jim Chandler, UDOT Region Four Resident Engineer for the project.  Project team members used a variety of communication and coordination strategies, common to all UDOT projects, to maintain the project scope, budget and schedule. For their efforts, project team members from UDOT and Granite Construction recently received an award for “Best Large Partnered Project” from the Utah Associated General Contractors.

Weekly team meetings – Regular meetings held at the contractor’s construction trailer allowed workers to update the rest of the team on construction processes. Participants included UDOT employees, contractor employees, sub contractors and third party stakeholders from the City of Monticello and utility companies.

Participants shared resolutions, safety concerns, and described upcoming construction impacts to the general public. The contractor reviewed all questions and concerns that were received from the general public – including road users and businesses along the corridor.

Team building – All project teams engage in formal and-or informal team building exercises. Formal team building exercises use a facilitator to forge relationships among team members and regular confidential, partnering surveys that rate communication and cooperation. Partnering surveys, with an average survey score of 19.28 out of 20, showed that the Monticello project team members valued each others’ contribution to the team.

While the project team didn’t employ formal team building, the informal team building efforts created a sense of unity and purpose among project workers.   Informal team building effort included close, purposeful collaboration among the project team members. Team members even socialized after hours.

Weekly email updates – The contractor the project sent weekly email updates to team members and area businesses to provide ongoing progress reports and to describe upcoming construction processes.

Be it resolved

Construction issues were resolved through a coordinated team effort. For example, the project team struggled with soft sub-grade and unknown, unmarked and abandoned drainage features. Old features, such as culverts and hydrants needed to be moved to make way for new drainage features. The aggressive schedule left little time for problem resolution. But, cooperation among team members prevented massive schedule delay as road features were encountered, excavated and moved. The project closed without any outstanding issues left to resolve.

Effective partnering also resulted in one half million dollars of savings. The project called for emulsion-stabilized full-depth reclamation. The contractor suggested switching to cement stabilized FDR as a value engineering change to save money without slowing down the project.

Congratulations to:

UDOT Project Manager Rustin Anderson

UDOT Resident Engineer Jim Chandler

The Moab Construction Office in conjunction with the Transportation Technicians from Moab, Monticello, Blanding and Bluff

Granite Project Manager Stephen Cordts

December 5th, 2011

TELEGRAPH STREET

1 Comment, Optimize Mobility, by Catherine Higgins.

UDOT used a quick and modern construction approach to improve traffic mobility and keep a historic look and feel in Washington City.

The new roadway on Telegraph Street in Washington City, Utah was made to have the feel of a bridge crossing with iron work and street lights.

Traffic used to slow abruptly on the two-lane Telegraph Street Bridge where four lanes narrowed to two. The  route experiences heavy traffic during peak commute times, and supports a thriving business center. Pioneer era buildings give the area a historic look and feel, and environmental study requirements called for a design that preserved that character.

Innovative construction

An arched culvert was built under the existing bridge while traffic on top continued to use the road during construction.

An ABC approach was used to widen the road to two lanes in each direction, and keep traffic moving during construction. UDOT has used many forms of ABC – this project used pre-formed concrete arch elements to build a giant culvert under the existing bridge while traffic on top continued to use the road during construction. UDOT’s contractor was able to keep one lane moving in each direction for the duration of the project.

“A local contractor secured the job by bidding an aggressive schedule and the construction management firm’s offices were also located right on the project,” says UDOT Region Two Public Involvement Manager Kevin Kitchen.

The quick 180 day schedule limited the inconvenience of construction on road users and businesses. “One local resident who has lived in the area for decades called to congratulate us,” says Kitchen. The resident claims “it was the best run construction project he’s ever seen from a driver’s perspective with traffic always moving and work always going.”

Old school

City officials are happy with the outcome too. “We couldn’t survive with two lanes,” says Michael Shaw,Washington Cities Public Works Director. “Telegraph is our downtown.” With only one lane in each direction, traffic slowed and made travel to and through the area unwelcoming.

The Washington City Museum is in the old city school, built in 1857.

The city was involved in planning the improvement right from the start. UDOT first met with city officials and residents with the objective of improving the road and turning over ownership to the city.

According to Shaw, UDOT incorporated everything the city wanted in the project, including replacing the bridge, a new road alignment, and city funded beautification elements. All together, the project created a wider tree-lined boulevard feel that has a traffic calming effect for motorists.

Building a new bridge would have been prohibitively expensive. Widening the old monolithic poured bridge was not possible, but a UDOT in-house design called for a culvert with an arched face to be built under the existing bridge. Fill around the culvert was faced with stonework, and new roadway was made to have the feel of a bridge crossing with iron work and street lights.

The new road has four lanes with a center median. The culvert accommodates a stream and pedestrian path. The project also included a number of city beautification improvements, including lighting, welcome signs and trees.

UDOT is in the process of turning ownership of Telegraph Street over to Washington City.

December 5th, 2011

ACEC EXCELLENCE AWARD

No Comments, Optimize Mobility, by Catherine Higgins.

Dal Hawks, foreground, gives legislators a tour of the I-15 CORE project

Dal Hawks, former project manager at UDOT is the 2012 Public Official of the Year.

The American Council of Engineering Companies has recognized Hawks for making significant contributions to the engineering profession.  ACEC chooses a Public Official of the Year based on the individuals’ commitment to public and community service, adding to the body of knowledge in an area of expertise, and exhibiting noteworthy leadership.

Hawks most recently managed the I-15 CORE project, the largest Design-Build project under construction in the nation. As Project Director, Hawks led a diverse, large and talented team to successfully deliver a high value public investment.

Some of the key accomplishments of the project team include:

  • Moving six bridge segments using Self Propelled Modular Transporters (SPMT).
  •   Employing fixed-price, best-design procurement, resulting in significantly more improvements than originally anticipated with impacts to the public minimized
  • Implementing key project systems to track and trend project performance
  • Developing and implementing key auditing system that allowed UDOT personnel the opportunity to oversee and monitor contractor and designer performance
  • Conducting risk workshops to identify, understand, assign and mitigate retained risks in order to enable UDOT to proactively manage the work within established and understood constraints
  • Conducting training on UDOT staff members’ roles and responsibilities, which will result in expanding institutional knowledge and expertise concerning the design-build contract method

Hawks has recently retired from UDOT.

Congratulations, Dal!

December 1st, 2011

UTAH WIND AND SNOW

1 Comment, Optimize Mobility, by Catherine Higgins.

UDOT weather, traffic, and communication experts teamed up to keep the public updated on extreme wind and snow.

Lisa Miller is the Travel Information Manager at UDOT's TOC.

UDOT’s coordinated approach kept the traveling public and road crews informed as high winds blew in the north and snow packed roads in the south. Weather and traveler information experts headquartered at the Traffic Operations Center — UDOT’s hub for collecting and distributing weather and traffic information.

The orchestrated effort “was a great example of diverse areas in the department working together to help make the transportation system better and safer for everyone,” said Carlos Braceras, UDOT’s Deputy Director.

Forecasts and observations

The UDOT weather team meteorologists made forecasts of  high winds and snow and contacted UDOT operations engineers to make sure all understood the seriousness of the weather message.

Knowing that heavy gusts were expected in east Layton, meteorologists placed a mobile weather station on U.S.-89 to fill a data and observation gap. During the event, meteorologists continued forecasts and observations and helped TOC operators to keep accurate messages on overhead signs and focused on putting out weather information tailored to the traveling public.

Snow in southern Utah slowed and closed parts of I-15, I-70, and SR-10 with ice and drifting snow. The extreme weather posed a challenge. For the most part, however, UDOT crews have been able to keep roads open.

Working together

[Tania on camera]

UDOT Public Information Officer Tania Mashburn

UDOT’s communications office began tweeting to get the word out on November 29. UDOT tweeps aimed at sending message every 15 minutes during the event.

Tania Mashburn, UDOT Public Information Officer, gave live media interviews every 5 to 10 minutes from 6 a.m. through early afternoon when the strongest winds subsided. Mashburn is the public face representing the ant hill of activity at the TOC. One challenge Mashburn and others faced was failure of some cameras due to the high winds. Information is more difficult to verify without all of the cameras. TOC operators compensated for the lack of visuals by using information from dispatchers, troopers and other responders, and issued official emergency alerts for closures and restrictions.

Travel Information Manager Lisa Miller is responsible for interfacing with many diverse groups, including UDOT crews and ports of entry, state and county law enforcement agencies and public groups, including truckers and emergency response groups. Miller and others at the TOC coordinated with an Emergency Operations Center in Centerville set up to coordinate response to the emergency. She also helped develop UDOT’s official message – a concise summary of road and weather information.

A hero to truckers

In a UDOT first, Trucking and Rail Planner Daniel Kuhn went into operations mode and helped truckers locate a place to park to wait out the wind or find an alternate route. A self starter, Kuhn started his day at 2 a.m. as traveling to truck stops and making an inventory of stalls. He spend hours contacting ports of entry and truck stops in surrounding states to direct truckers around the problem areas.

December 1st, 2011

THESE GO TO 11

5 Comments, Uncategorized, by Catherine Higgins.

UDOT signs may soon be more retroreflective.

Many freeway signs don’t need active lighting due to the high level of retroreflectivity of sign materials.

Gone are the days when all freeway signs require active lighting to be seen at night. The sheeting material used to face modern signs is highly retroreflective — meaning the light bounces off of the sign right back to the light source. Many freeway signs don’t need active lighting due to the high level of retroreflectivity of sign materials.

UDOT requires that signs be faced with retroreflective Type 9 sheeting. New Type 11 sheeting, which has a higher level of retroreflectivity, can be used. Contractors who bid for UDOT projects can select the most appropriate sheeting for the job.

UDOT uses active lighting on all system to system interchanges and other places where the roadway is complicated or the signs use a lot of text. For example, the I-15 to I-80 interchange in Salt Lake County has active lighting to assist state-to-state motorists. For other locations, UDOT uses active lighting on a case-by-case basis. Motorists who observe lighting fixtures that may not be working as intended should call 801-975-4000 to report the location.

Observations

Retroreflectivity on signs can be diminished over time due to weather, vandalism or other damage. Ongoing evaluation of signs, especially those that have been in place for several years, is important to maintaining safety on UDOT facilities.  At UDOT, maintenance workers conduct inspections as part of an overall plan to make sure signs meet new federal standards.

Visual inspection at night is critical when evaluating how effectively retroreflective signs are doing their job. Signs with small areas of damage may be readable during the day, but “the effect of that damage at night could be huge” says UDOT Operations Design Engineer Wes Starkenburg. For example, a paint ball hit can prevent the reflective material from shining in headlights.

A retroreflectometer can be used to take objective measurements. Several measuring devices are available – some require actual contact with the material being measured.

When signs get too old, worn or damaged, single signs are replaced, but typically UDOT identifies interstate segments where a series of signs could be improved. Replacing signs in a segment gives UDOT the chance to update signs that work together to provide clarity and consistency for road users.

Innovations

UDOT uses materials that have been tested by ASTM International, an organization that tests products to set standards for many industries. Sheeting materials are tested in a lab that’s set up to approximate how road users will see signs at night with headlights. Testers evaluate sheeting attributes including color, gloss, opacity, and texture, and take objective measurements.

November 30th, 2011

UDOT TRAFFIC

4 Comments, Optimize Mobility, by Catherine Higgins.

UDOT roads are smart.

Cables buried along freeways and major surface streets  send information to a sophisticated computerized system that monitors and manages traffic flow. The CommuterLink website is the public face of the system, and road users have depended on the website to steer clear of traffic delay by getting up to the minute information about weather, road construction and crashes.

Now, smart phone users can have convenient access to the same information by using UDOT’s new app,  UDOT Traffic. The free app is available at the iTunes Store and Android Market and includes:

  • A  Google Maps display
  • Traffic conditions
  • Crashes, construction and hazards
  • Special events
  • Road weather and forecasts
  • Seasonal road closures
  • Traffic camera images
  • Roadway sign messages

    A new app, UDOT Traffic, features a Google Maps display

 Help UDOT reach the ZERO Fatalities goal — never use this app while driving.