Category Archives: Optimize Mobility

Grouted Splice Sleeve Connectors for ABC Bridge Joints in High-Seismic Regions

Photos and diagram of different kinds of GSS connectors

Figure 1. Two types of GSS connectors used: (a) FGSS, (b) GGSS, (c) FGSS-1, (d) GGSS-1

In recent years, the Accelerated Bridge Construction (ABC) method has received attention in regions of moderate-to-high seismicity. Prefabrication of bridge structural components is a highly effective method in this process and one of the ABC methods for Prefabricated Bridge Elements and Systems (PBES) advanced by the Federal Highway Administration. Joints between such precast concrete components play an important role in the overall seismic performance of bridges constructed with the ABC method. Research has been carried out at the University of Utah to investigate potential ABC joint details for bridges located in high-seismic regions. A connector type, referred to as a Grouted Splice Sleeve (GSS), is studied for column-to-footing and column-to-cap beam joints. Two GSS connectors commonly used in buildings were utilized in this study, as shown in Fig. 1. The column-to-cap beam joints used a GSS connector where one bar was threaded into one end and the other bar was grouted into the opposite end (denoted as FGSS), as shown in Fig. 1(a) and Fig. 1(c). The column-to-footing joints incorporated another type of GSS where the bars were grouted at both ends (denoted as GGSS), as shown in Fig. 1(b) and Fig. 1(d).

Drawings of the test specimen alternatives

Figure 2. Configuration of test specimen alternatives

Three precast alternatives in addition to one conventional cast-in-place half-scale model were constructed for each category, as shown in Fig. 2; the column-to-cap beam joints were tested upside down. The GSS connectors were placed in the column base (GGSS-1) or column top (FGSS-1) in the first alternative. The location of the GSS connectors changed to the top of the footing (GGSS-2) and bottom of the cap beam (FGSS-2) to study the performance of the joints when the GSS connectors were outside the plastic hinge zone of the column in the second alternative. The dowel bars in the footing and the cap beam were debonded over a length equal to eight times the rebar diameter (8db) for the third alternative in both categories, while the GSS connectors were embedded in the column base (GGSS-3) or column top (FGSS-3). The last specimen type was the cast-in-place joint, in which continuous bars from the footing and cap beam were used to build the columns with-out bar splices (GGSS-CIP and FGSS-CIP).

Photos of the speciment

Figure 3. Specimen GGSS-3 at a drift ration of 7%: (a) overall view; (b) footing dowel at joint interface

Experimental results under cyclic quasi-static loading showed that the performance of all joints was satisfactory in terms of strength and stiffness characteristics. However, the hysteretic performance and displacement ductility capacity of the specimens were distinct. Improved seismic response was observed when the GSS connectors were located inside the footing (GGSS-2) and the cap beam (FGSS-2) rather than the corresponding column end. The debonded rebar zone enhanced the ductility level and the hysteretic performance of the joints. This technique was found to be highly effective for the column-to-footing joint (GGSS-3), as shown in Fig. 3. As expected, the cast-in-place joints performed the best.

Even though AASHTO Specifications currently do not allow the use of connectors in the plastic hinge region, all joints tested in this research demonstrated acceptable ductility for moderate-seismic regions and some joints demonstrated acceptable ductility for high-seismic regions. The GSS connectors studied in this research were promising, especially when considering the time-saving potential of joints constructed using ABC methods; however, the different hysteretic performance and reduced displacement ductility of various alternatives com-pared to the cast-in-place joints must be accounted for in design.

Acknowledgments: This study is described further, including recent reports, on the TPF-5(257) website. The authors acknowledge the financial support of the Utah, New York State and Texas Departments of Transportation, and the Mountain Plains Consortium. The authors also acknowledge the assistance of Joel Parks, Dylan Brown, and Mark Bryant of the University of Utah.

This guest post was written by Chris P. Pantelides, Ph.D., University of Utah, M.J. Ameli, University of Utah, and Jason Richins, S.E., Research Engineering Manager and was originally published in the Research Newsletter

400 South Corridor Assessment

LRT Study

Figure 1. Roadway and LRT Study Network

This study evaluated current and future traffic and transit performance along the light rail transit (LRT) corridors within the University of Utah area, 400 South and Downtown Salt Lake City before and after an introduction of an additional LRT line. The analysis of different scenarios and on different network levels was performed using VISSIM microsimulation coupled with Siemens Next-Phase Software-in-the-Loop traffic controllers. The scenarios were evaluated for three different target years: 2013/2014, 2020 and 2025. Additional scenarios included alternative intersection configuration, with modified left turn operations at intersections of 400 South and Main, 400 South and State, and 400 South and 700 East.

Screenshot of the intersection simulation

Figure 2. Main Street and 400 South Intersection in Simulation

The analysis showed that the additional LRT line did not have significant impacts on traffic and transit operations. The highest impacts were experienced at intersections close to the Downtown area, mainly 400 South and State Street, and 400 South and Main Street, and North Temple and 400 West. The study also recommended potential signal improvements at these locations consisting of re-phasing, re-timing and modifying LRT preemption. The analysis also showed that it might be beneficial removing the shared lane sites at intersections along 400 South, since close to 70% of drivers are using the non-shared left turn lane, resulting in sub-optimal intersection operations.

This study was coordinated between UDOT, Utah Transit Authority, and other agencies.

This guest post was written by Milan Zlatkovic, University of Utah, Ivana Tasic, University of Utah, Marija Ostojic, Florida Atlantic University, and Aleksander Stevanovic, Florida Atlantic University, and was originally published in the Research Newsletter.

UDOT Citizen Reporter Program gathers volunteer data

Citizen Reporting LogoThe UDOT Citizen Reporting Program enlists volunteers to report on current road conditions along specific roadway segments across Utah. Since the program’s launch in November 2013, UDOT has received over 1,800 road condition reports on critical routes throughout the state. The accuracy rate of the reports continues to be very high, with only 0.03% of incoming reports determined to be inaccurate.

The long term goal of adding Citizen Reporters to UDOT’s weather operations road reporting is to supplement current condition reporting on segments where drivers are already traveling. The Citizen Reporter Program provides the traveling public with a conduit to report their observations directly to UDOT, saving time and money. UDOT employees also use the Citizen Reporting app to submit their reports.

Since the UDOT Citizen Reporter Program was launched volunteer reporters have submitted reports on 119 of the 145 road segments, helping to fill in gaps in locations where UDOT does not have traffic cameras or Road Weather Information System (RWIS) units.

Graph showing citizen reports by day. The most were received in Decemenger 2013.The volunteer reports are especially valuable during winter storms when conditions change rapidly. During a large winter storm that occurred in the beginning of December 2013, UDOT Citizen Reporters submitted over 130 reports, helping the traveling public as well as National Weather Service meteorologists and UDOT staff.

How do you become a UDOT Citizen Reporter?

In order to become a UDOT Citizen Reporter, you will need to complete a brief training (either online or in person), take a short quiz and complete a sign-up form. The training takes approximately 10 minutes to complete. Once a volunteer has completed these steps, they will be provided with a login and PIN, and can begin submitting reports. Reports are submitted through the UDOT Citizen Reporting app, downloadable for Android and Apple devices from the Apple App Store or Google Play Store.

If you would like to become a Citizen Reporter, please follow this link to take the online training: www.udottraffic.utah.gov/training/citizenreporter. For more information or to schedule an in person training, email UDOTCitizenReporter@utah.gov.

State Street Project adds Bike Lanes through Local Government Input

When Region Three began preparations for reconstructing State Street from 1860 North in Orem to 100 East in Pleasant Grove, the focus was on widening to three travel lanes in each direction plus a center turn lane.

The project team prepared plans for new asphalt pavement; traffic signal upgrades; curb, gutter, sidewalk and pedestrian ramp installations and reconstruction of the intersection at State Street and 400 North in Lindon. But what makes this project memorable was the partnership with the cities of Orem, Lindon and Pleasant Grove that brought about the addition of striped bicycle lanes to the project scope.

“We have been working with UDOT Central Planning and Mountainland Association of Governments to identify opportunities for bike improvements,” said Region Three Program Manager Brent Schvaneveldt.

“With UDOT’s emphasis on integrated transportation and these other bicycle connectivity discussions happening, we wanted to take the cities’ request for bike lanes seriously and take a hard look at whether they could be added into the design and construction.”

With the widening, repaving and re-striping already planned for State Street, the opportunity to reallocate space and stripe bike lanes made sense. But it wouldn’t have happened without the buy-in and support from local governments.

“Local government collaboration is key to making our transportation network work for the people who use it. Especially on a roadway like State Street that serves local trips as well as regional travel,” Brent said. “This is a great example of local government input helping us better serve the needs of a variety of roadway users.”

UDOT’s Incident Management Team participates in Emergency Vehicle Training

Photo of all of the IMT trucks lined upUDOT’s Incident Management Team (IMT) vehicles exist to help motorists when they have car trouble and to support the Utah Highway Patrol (UHP) during any roadway incident. UDOT is focused on quick clearance of traffic incidents to minimize the risk to the first responders and to have travel lanes reopened as soon as possible.

UDOT’s IMT program has 14 trucks operating in all four of UDOT’s regions. The trucks carry a variety of equipment, including jacks, gasoline, air compressors, battery packs, oil dry, first aid kits and various tools for minor roadside repairs. UDOT chose to operate larger vehicles than some other states for the IMT program. The benefits are better visibility to passing motorists and the ability to carry more equipment.

Image of Twitter comment thanking an IMT driver for help chaning a tire.

A thank you received by UDOT Traffic on Twitter

IMT drivers are required to attend several trainings per year including training on hazardous material spills, emergency traffic control, medical and FEMA classes. Recently, the IMT drivers completed their certifications in emergency vehicle operations at the UHP training track near Camp Williams. The drivers learned about proper backing techniques, defensive driving, their vehicle dynamics and proper emergency traffic scene safety.

Image of a tweet sent thanking IMT for they help while stranded on I-80 near the airport.

Thank you recived by UDOT Traffic on Twitter.

The IMT program has helped hundreds of motorists over the last several years. Some people refer to the IMT drivers as “professional good samaritans.” Disabled vehicles on a freeway create a safety hazard, especially when the disabled vehicle is blocking a travel lane. The likelihood of a secondary crash resulting from congestion increases by almost 3% for every minute that the lane is blocked. Approximately 20% of all crashes are called secondary crashes, or a crash that can be traced to an original incident.

This guest post was written by Jeff Reynolds, Roadway Safety Manager.

Highlights from the 2013 Annual Efficiencies Report

Efficiencies within UDOT often generate cost savings for the public and the Department through better utilization of resources and innovative technologies. At the end of each year, UDOT prepares an efficiencies report which summarizes key efficiency initiatives from the year. The annual report fulfills a requirement for UDOT to describe the efficiencies and significant accomplishments achieved during the past year to the State Legislature. UDOT Senior Leaders use the report in presentations during legislative committee meetings.

Following are the key efficiency initiatives summarized in the FY 2013 report:

  • Bicycle Detection and Pavement Markings
  • Flashing Yellow Arrow for Left Turns
  • Reflectorized Yellow Tape on Signal-Head Back Plates
  • Portable Weather Station for Advance Warning of Debris Flows
  • Audio Over IP Highway Advisory Radio in Utah County
  • Commercial Vehicle Bypass (PrePass)
  • Partnered Fiber-Optic Cable Installations
  • Resolving Utility Conflicts through a Preserve and Protect Approach
  • Utah Prairie Dog Programmatic Agreement
  • Performance-Driven Programming
  • Energy-Efficient LED Lighting Upgrades in Department Facilities
  • iMAP GIS Tool
  • Improved Decision Making Using Mobile Data Collection
  • MMQA Data Collection Teams
Photo of a flashing yellow signal

Flashing Yellow Arrow left-turn phasing

One example from the 2013 report is the improved safety at intersections that are changed from Protected/Permissive to Flashing Yellow Arrow left-turn phasing. UDOT and other jurisdictions throughout Utah are among the first in the nation to implement flashing left-turn arrows. Potential annual public cost savings per installation ranges from $17,745 to $2,769,000 from reduced crashes.

Photo of rock and mud covering the highway

Debris flow across S.R. 31 in Huntington Canyon

Another example from 2013 is the use of a portable weather station to provide advance warning of debris flows and flooding at the Seeley burn scar near S.R. 31 in Huntington Canyon. Using the station contributed to over-all safety, minimized equipment losses, reduced response time, and minimized impact to commerce. An estimated $50,000 was saved through reduced risk to field crews, motorists, and equipment.

UDOT Research Division staff coordinate each year with UDOT Senior Leaders and the Communications Office to collect and compile write-ups on the past year’s key efficiency initiatives. This process will start again in August for FY 2014. We look forward to receiving “game changing” efficiency topics from all Regions and Groups that will potentially be included in the annual report.

The 2013 and earlier annual reports are available online at www.udot.utah.gov/go/efficiencies.

This guest post was written by David Stevens, P.E., Research Project Manager, and was originally published in the Research Newsletter.

Region Three Traffic Signal Update nearly Complete

Photo of the State Street and 1320 South intersection in Provo

New signals at Provo State Street and 1320 South.

Existing traffic signals have been updated to newer equipment that includes controllers that send real-time data about the signal operations to the Traffic Operations Center.

With the upgraded controllers, UDOT can troubleshoot issues remotely such as noticing a stuck pedestrian button or verifying signal timing.

Traffic engineers can track data that used to require manual labor such as traffic speeds, traffic volumes and percent arrival on green.

Photo of the inside of a signal cabinet

A signal cabinet at State Street and 1320 South. The cabinet contains a controller that gathers and transmits real-time traffic data for remote analysis and optimization of the system.

Out of 249 signals operated by UDOT in Region Three, 211 have been upgraded to gather this real-time traffic data for analysis and optimization of the system. “Small adjustments can sometimes make a big difference for our traffic operations,” said
Adam Lough, Region Three Engineering Manager.

“The upgraded signal controllers allow us to make these adjustments and monitor how the intersection is operating without being on-site.”

Results of the 2014 Research Workshop (UTRAC)

Photo of session attendees listening to speaker

Traffic Management & Safety breakout session

Projects have been selected for FY15 funding from the 2014 UDOT Research Workshop held on April 30th.

Fifty-nine problem statements were submitted this year for the UDOT Research Workshop. Of these, 16 will be funded as new research projects through the Research Division. Some submitted problem statements will be funded directly by other divisions.

The workshop serves as one step in the research project selection process which involves UDOT, FHWA, universities, and others. UDOT Research Division solicited problem statements for six subject areas: Materials & Pavements, Maintenance, Traffic Management & Safety, Structures & Geotechnical, Preconstruction, and Planning.

At the workshop, transportation professionals met to prioritize problem statements in order to select the ones most suitable to become research projects.

After the workshop, UDOT Research Division staff reviewed prioritization and funding for each recommended problem statement with division and group leaders and presented the list of new projects to the UTRAC Council.

The selected new projects include:

  • Asphalt Mix Fatigue Testing using the Asphalt Mix Performance Tester (CMETG)
  • Developing a Low Shrinkage, High Creep Concrete for Infrastructure Repair (USU)
  • Prevention of Low Temperature Cracking of Pavements (U of U)
  • Review and Specification for Shrinkage Cracks of Bridge Decks (U of U)
  • Incorporating Maintenance Costs and Considerations into Highway Design Decisions (U of U)
  • Unconventional Application of Snow Fence (UDOT)
  • Statistical Analysis and Sampling Standards for MMQA (U of U)
  • National Best Practices in Safety (UDOT)
  • I-15 HOT Lane Study – Phase II (BYU)
  • Characteristics of High Risk Intersections for Pedestrians and Cyclists-Part 3 (Active Planning)
  • Safety Effects of Protected and Protected/Permitted
  • Left-Turn Phases (U of U)
  • Development of a Concrete Bridge Deck Preservation Guide (BYU)
  • TPF-5(272) Evaluation of Lateral Pile Resistance Near MSE Walls at a Dedicated Wall Site (BYU)
  • Active Transportation – Bicycle Corridors vs. Vehicle Lanes (BYU)
  • Investigating the Potential Revenue Impacts from High-Efficiency Vehicles in Utah (UDOT)
  • Developing a Rubric and Best Practices for Conducting Bicycle Counts (Active Planning)

At the April 30th workshop, Dr. Michael Darter of Applied Research Associates gave an inspiring keynote ad-dress on collaboration between state DOTs and academia in developing innovative ideas. Also at the workshop, Barry Sharp, recently retired from UDOT, was presented with the UTRAC Trailblazer Award for his significant contributions towards improving UDOT research processes and the use of innovative products in transportation. Russ Scovil was our workshop coordinator and did a great job.

We appreciate everyone’s participation in the work-shop process. The new research projects can start as early as July 2014 in coordination with UDOT Research staff and champions.

To see details on the new projects and all submitted problem statements, visit the UDOT Research Division website.

This guest post was written David Stevens, P.E., Research Project Manager, and was originally published in the Research Newsletter.

Uinta Rail & Roads Project Underway

Photo of a tanker truck going down the road.

A tanker drives through a pavement project on U.S. 40 in Vernal — one strategy to meet future transportation needs in the Uinta Basin is to define a standard cross section for consistent lane widths and shoulders.

UDOT Region Three has a leadership role in planning for the future transportation needs of the Uinta Basin, including Uintah and Duchesne counties.

With planned growth in the Basin, the Uinta Rail and Roads project was initiated to look at different transportation options to enhance economic development.

Craig Hancock, Region Three Engineering Manager, is leading the roads analysis, which is scheduled to be complete late-summer. The project team has been evaluating data including traffic volumes, crash data and pavement conditions in order to prioritize future projects. The results of the study will be incorporated into UDOT’s Long Range Planning process.

John Thomas, Region Three Engineering Manager, is leading the rail EIS project team, which is preparing to publish a Notice of Intent later this year to formally begin the environmental study.

As a rail project, the study will have a different joint-lead than FHWA and likely follow different guidelines and procedures from typical UDOT environmental studies. A draft Environmental Impact Statement (EIS) is anticipated in 2016.

UDOT Traffic Alerts

Screen shot of the My Alerts webpageThe Utah Department of Transportation Traffic Management Division has enhanced the UDOT Traffic Alerts program. Now, motorists can receive customized email, text or push notifications to help them stay informed regarding lane closures due to construction, crashes and weather.

The new UDOT Traffic Alerts program allows motorists to customize their profile and receive alerts for specific routes and times of day. In addition to lane closure information, a profile can be customized to receive seasonal road closure information, Amber Alert notifications, TravelWise Alerts for major impacts and Emergency Alerts for critical closure information.

To customize your profile and start receiving alerts, visit www.udottraffic.utah.gov and click on the “MY  UDOT Traffic Alerts” tab in the upper right corner. Then, register your device and begin selecting your notifications. If you have questions, please contact askudottraffic@utah.gov.

Frequently Asked Questions:

Why must I register?

  • Registration gives you the ability to fully customize your experience within our website. As a registered user, you may choose the maps you wish to display, along with a host of other options to give you the information you need, right now. Note: both your username and email address must be unique.

How does the system work?

  • Once you have specified your My UDOT Traffic settings, you have the option to view your custom page rather than the default view. Users may change their options at any time.

Will my email address be given to any third parties?

  • No! Your email address is gathered for the sole purpose of uniquely identifying your account, and will not be disseminated to any third parties under any circumstances.

Additional Information:

  • Cell phone numbers and cell phone service providers are needed for sending UDOT Traffic Alert text messages to My UDOT Traffic users. Signing up for UDOT Traffic Alert text messages is optional.
  • UDOT does not provide personal information about our website visitors to any third parties for any purpose.