BRIDGE SMARTS

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.

NEW MATH

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.

WE CAN WORK IT OUT

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

TELEGRAPH STREET

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.

ACEC EXCELLENCE AWARD

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!

UTAH WIND AND SNOW

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.

THESE GO TO 11

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.

UDOT TRAFFIC

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 Google Play 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.

REBUILDING SR-14

A major landslide that closed State Route 14 put a massive rebuilding effort in motion at UDOT.

An aerial photo shows the magnitude of the slide area. Rebuilding the road will involve moving and compacting material to reestablish the road grade.

The substantial area of the slide, huge house-sized boulders and the geology of the area will present challenges to the contractor that will be chosen to rebuild the road. A team of UDOT engineers, along with local design and construction experts, will conduct preliminary investigations and use an innovative contracting method to accelerate the removal of the landslide material in a safe manner, re-establish the stream bed and construct a new road.

David Fadling, UDOT engineer and Lead Geologist, is working with a team of investigators to install monitoring equipment and take samples of the slide material for testing. “Our main concern is stability,” says Fadling. “If the slide is still moving, we would like to know the depth of the sliding.” Inclinometer casing will be installed to monitor lateral movement in the ground. Piezometers will be installed to help locate the depth of ground water in the area.

Fadling’s team will also investigate on site materials in order to to define material properties and to identify the sliding surface. “We suspect shale is the culprit weak layer on which sliding initiated and groundwater is almost surely a contributing factor.”  Shale is a sedimentary rock with fine clay particles.  The type of material and groundwater will be taken into account as engineers plan how to clear the landslide and build the new road.

Moving earth

It is likely the material will be moved from the top of the slide and used to buttress the recovered road grade.

Building the road will involve moving and compacting material to reestablish the road grade. Fadling anticipates that some of the large boulders may have to be blasted and moved with large bulldozers and some will be pushed or rolled down the hill.  “The contractor will likely use gravity as much as possible to assist in moving large blocks of rock,” he says.

It is likely the material will be moved from the top of the slide and used to buttress the recovered road grade. Material used as sub grade for the road will need to be thoroughly compacted to guard against settlement.

Innovative contracting

UDOT’s uses a variety of contracting methods that factor in user costs, encourage innovation and speed, and seek a balance point for everyone, including the contractor and the general public. UDOT will use a Construction Manager General Contractor method for the SR-14 project.

The CMGC contracting process forges a partnership during the design phase among UDOT, the designer working for UDOT, and a competitively selected construction contractor. By using CMGC, UDOT will minimize risk to the contractor, develop a project schedule, identify potential innovations, and determine cost.

After the design phase, the CMGC process allows UDOT  to give the construction contractor involved during design the first opportunity to price the work. An independent cost estimator, along with UDOT’s Engineers Estimate, will be used to evaluate the contractor’s pricing making sure UDOT obtains a fair price.

Alternate routes

UDOT maintenance crews are aware of the importance of SR-14 to road users who access cabins and recreation areas. “Meanwhile, maintenance crews are gearing up to take on Mother Nature on S.R. 143,” states a recent Region Four newsletter article. ” The goal is to keep alternative access to the mountain available with the exception of extreme weather events. ” UDOT will coordinate with the National Park Service and National Forest Service.  Seasonal closures occur on both SR-14 and 148. Consult UDOT’s CommuterLink Website for up-to-date information about seasonal closures.


Created with Admarket’s flickrSLiDR.

For more:

  • Here is a Link to the UDOT Region Four Newsletter with a more detailed article.
  • See a video on KSL.com.

 

 

PED SCRAMBLE

Matthew Luker, in reflective gear, stands by an open signal box near the U of U. During special events, operators may have to keep close watch on traffic, and sometimes, be on-site to make sure traffic moves smoothly.

UDOT traffic engineers take special care to accommodate vehicle and pedestrian traffic generated by special events.

The holiday season can be challenging with concerts, holiday shopping, Jazz games, happening together and creating “competing demands for the transportation system,” says Matthew Luker, Signal Systems Engineer at UDOT. Preventing gridlock is the job of Luker and other traffic engineers who watch signal operations from a remote location and if required, and trouble-shoot timing at the signal location if necessary.

UDOT’s 1200 signals are operated through a centralized Traffic Operations Center. Signals are synchronized with each other by time of day. Each signal can operate using multiple signal coordination plans that correspond to traffic needs.

Signals are programmed to automatically switch from one signal coordination plan to another throughout the day– for example, signals can be programmed to allow more green light time in the peak traffic-direction during the morning or evening commute.

Pedestrian traffic at the U is accommodated by setting all four signals to the crossing phase at once allowing pedestrians to cross diagonally in a "ped scramble."

Signal operators can program several coordination plans per signal. With 1200 signals to synchronize statewide, creating plans for each signal takes a lot of time and effort.

First, an on-site vehicle count is completed at each intersection. Data from that count is analyzed and engineers draw conclusions that form the basis for each coordination plan.

In addition to programming signal coordination plans, TOC signal operators can also make manual adjustments to help traffic during major incidents or events, such as a crash that blocks travel lanes or a football game that draws fans to the game.

Heavy directional commute traffic can be anticipated each week day but special events throw a monkey wrench into the mix. Often, an evening commute plan will be put in place to accommodate special event traffic. When multiple events coincide, such as a concert and a basketball game in Salt Lake, operators may have to keep close watch on traffic, and sometimes, be on-site to make quick changes.