Tag Archives: Traffic Operations Center

UDOT app wins award for digital pioneering

SALT LAKE CITY — The pioneering sprit has always been in Utah’s blood. From the Winchester rifle, Word Perfect and wider Pioneer Streets, to the Roadometer and Television, Utah has always tried to be at the forefront of technology.

In the digital age, the Utah Department of Transportation (UDOT) has continued as a technological pioneer, especially in the field of Intelligent Transport Systems (ITS). It was recently awarded a “Best of ITS” award by the ITS World Congress this fall for its Citizen Reporter app, which was piloted during the 2012-2013 winter season.

Citizen Report Screenshot

A screenshot of the Citizen Report app

The app, which is the first of its kind in the United States, is aimed at Keeping Utah Moving, specifically during winter months. It allows citizen volunteers to report on road weather conditions along specific roadways across the Beehive State, after a short training session. These reports give enhanced road weather information to travelers when the stakes are the highest — during inclement weather. 

In large, sparsely populated states like Utah, state DOTs have trouble providing up-to-the-minute accuracy on road conditions to travelers. It’s especially tough in Utah, where nearly 1,000 cameras statewide still can’t see every inch of roadway. But that’s where crowd sourcing from citizen reporters comes in, providing more accurate and timely information to the traveling public on conditions around the state.

Lisa Miller, UDOT’s Traveler Information Manager, said the program was extremely successful, with over 1100 reports last year from approximately 500 reporters. She predicts four times the usage of the app this coming year.

“Our early concern was that the data might not be reliable,” Miller said. “But what we’ve found is that the incoming data is 99% accurate.”

Other states, such as Idaho, Iowa, Kentucky, Michigan, Montana, Nebraska and North Dakota have requested information from UDOT to create similar programs in those states. The success of the program has spurred the department to produce another app, called Click N Fix, which allows the public to report potholes, burnt out highway lights, and other safety issues. The app will be more widely available to the public in early 2015.

The 2014 ITS World Congress

UDOT was awarded a “Best of ITS” award for “Best New Innovative Practice” in September.

“Crowd-sourcing is emerging as an effective means to both engage and serve the public, Miller said. “The public can now make more informed travel decisions, which impacts everything: safety, mobility, and the economy.”

To become a 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.

You can download the Citizen Reports app for your iPhone or Android device.

Nevada I-15 flooding required a multi-state response

A two-mile stretch of I-15 near milepost 91 in Nevada was washed away due to heavy rainfall that started on Monday, September 8th. In an unprecedented storm around 4 inches of rain fell in the space of 2 hours, flooding the road and washing away ground and asphalt leaving the interstate impassable. Record breaking numbers of rainfall were reported along streams in the area.

The Nevada DOT declared a state of emergency on Tuesday, September 9 due to the importance of passenger vehicle and commercial trucking flow on I-15. According to Arizona Department of Transportation, approximately 23,000 vehicles use I-15 each day between St. George, Utah and Las Vegas, Nevada.

Warnings on Utah’s freeway message boards were posted up and down I-15 letting drivers know that the freeway would be closed down and provided details for  alternate routes. These signs went as far east as Nebraska to provide enough time for travelers to change their routes.

Screen shot of tweet that says 'From nevadadot semi restriction lifted (except oversie w/o permit) on NV I-15Information was also available to drivers via the 511 phone line, the Utah Trucking Association, news outlets, Arizona and Nevada DOT’s, the UDOT Traffic website, the UDOT Traffic Twitter account and the UDOT Traffic app. UDOT’s social media channels proved very valuable during this event.

Travelers were directed to take S.R. 56 out of Cedar City to Nevada S.R. 319 and then to the U.S. 93 back to the freeway. UDOT and NDOT worked very hard to provide accurate and timely information to motorists traveling on this alternative.

State DOT’s had to work together. Although the closure was not in Utah UDOT was heavily involved in sending support to the affected areas. Due to increased traffic on S.R. 56 a UDOT Incident Management Team (IMT) was dispatched to assist. The IMT crews directed traffic, filled potholes and moved disabled semis out of traffic.

They also deployed a portable traffic camera trailer to the S.R. 18/S.R. 56 junction to monitor any potential problems and back-ups. UDOT’s Region 4 shared access to this camera with Nevada DOT. Region 4 was also able to respond quickly to a rockslide on the Arizona section of I-15 and sent snow plows to clear rock debris in the Virgin River Gorge area.

Southbound I-15 reopened to traffic on Friday, September 12th to one lane in each direction for passenger vehicles. Northbound lanes reopened on September 18.

Glenn Blackwelder a Traffic Operations Engineer at UDOT said “We could not have done it on our own. It took the communication and resources of the Traffic Operations Center, Region 4 and NDOT working together. We were pleased with how all agencies and divisions were able to work together to get I-15 back open as quickly as possible.”Screen shot of tweet and attached map showing detour route. The tweet reads "Reminder: Nevada I-15 closed due to flooding. So Cal and Vegas detour map:"

This guest post was written by Adam McMillan, Traffic Operations Center Intern.

Incident Management Team celebrates 20 years of service

If you’ve ever had a flat tire, run out of gas, or driven by a crash on Utah’s roadways, chances are you’ve seen the white Incident Management trucks loaded with orange traffic cones, their electronic signs on the top with vital information. An integral part of how the state deals with time-sapping events on our roadways, UDOT’s Incident Management Team has 15 teams on call statewide for just about anything that can happen.

But it wasn’t always that way: After 20 years, it’s time to celebrate the service of the unsung heroes of the IMT team.

Incident Management Team

IMT members Billy Frashure, Nick Jarrett, Mark Whittaker, Jeff Reynolds and Alan Peterson are some of the professionals keeping Utah drivers safe. Photo by Adan Carrillo

In 1994, UDOT started a courtesy patrol — two trucks assigned to help drivers in the Salt Lake Area. But time and demand have increased the IMT’s role. No longer is the team looked at as a courtesy — but a necessity — in keeping Utah freeways safe and traffic moving from Logan to St. George and everywhere in between.

Consider this: since 2004, the IMT has helped more than 120,000 motorists in the Beehive State. With these professionals specifically trained in clearing crashes off the road quickly and then staying on the scene, emergency personnel and the Highway Patrol can focus on what they do best while knowing IMT is protecting them on the road.

Another important stat: with each minute saved by clearing a crash, five minutes of delays are prevented. Clearing crashes also helps prevent secondary crashes.

“Think of how many drivers have been helped since 1994, how many injuries have been prevented, or lives saved?” said UDOT Executive Director Carlos Braceras during a celebration on Monday. “IMT is a critical piece to help us reach our goal of Zero Fatalities.”

Braceras went on to give all of us safety tips to help IMT and UDOT out with the goal of Zero Fatalities on Utah roads:

  • Don’t stop on the freeway unless it’s an emergency
  • If you ARE involved in an incident, stay in your car with your seat belt on.
  • Slow down and move over to the next lane if you see a vehicle on the side of the road — it’s the law to do so for emergency vehicles.
  • Make sure you have enough fuel to make your trip safely
  • Check your spare tire to see if it’s in working condition
  • Prepare for the worst weather by keeping a blanket, food and water in the car.
  • Leave a lot of distance between you and the car in front of you.
Five Incident Management Team Vehicles offered the media ride-alongs to give them a better idea of what it’s like to be an IMT professional. Photo by Adan Carrillo.

Five Incident Management Team Vehicles offered the media ride-alongs to give them a better idea of what it’s like to be an IMT professional. Photo by Adan Carrillo.

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.”

Silver Barrel for Life Saving Efforts

Photo of Executive Director with Thomas and LorenAt 2:30 p.m, Friday April 25, 2014, two UDOT Advanced Traffic Management System (ATMS) maintenance crew members were pulling communications cable at 2600 South and 700 East in Salt Lake City. This project is being coordinated with Salt Lake City in an effort to establish radio communications with some of Salt Lake City’s traffic signals.

While performing this routine duty, Thomas Hammon and Loren Jackson noticed an eldery man in distress. Thomas and Loren were not the first good Samaritans on the scene, however when they arrived, they were able to take charge of the situation and assist the man. Thomas spoke with the 911 dispatch operator while Loren attended to the elderly man who was now laying on the ground. Loren was able to give vital signs to Thomas who relayed the information to the 911 operator. Shortly after arriving at the scene, the elderly man did not have a pulse, so Loren checked the airway for obstructions and began CPR. Loren and Thomas tag-teamed the CPR for 7 to 10 minutes before United Fire Station #101 and Gold Cross Ambulance arrived on the scene. After being relieved from CPR, Thomas and Loren gave statements of the incident to Salt Lake Police and resumed their job duties.

Loren and Thomas have both taken advantage of the free CPR training offered through UDOT and put it to good use. Loren and Thomas acted quickly and took control of this situation. JT Dziatlik supervises Loren and Thomas and said, “Loren and Tom went above and beyond their job descriptions trying to save a life. They are an excellent example of UDOT employees who make a difference in everyday life.”

Optimizing Mobility

As we continually look for ways to improve our processes with the ultimate goal of keeping drivers moving on Utah’s roads, UDOT has deployed a number of technological tools that align with our strategic direction to preserve infrastructure, optimize mobility, reach our goal of zero fatalities, and strengthen the economy. I wanted to particularly emphasize what we are currently doing as a department in regards to our goal of optimizing mobility, which, in our day and age, no longer only applies to people’s ability to keep moving but also to their ability to do things as they are moving (but not driving), via phone apps.

These UDOT phone apps are allowing citizens to perform a variety of tasks, like reporting road conditions directly to operators at the Traffic Operations Center (TOC), or finding out what kind of delays to expect due to construction projects, and receiving severe weather event warnings. In addition to this ever evolving field of mobile technology, we continue to rely on innovative projects based on traffic models and engineering to not only improve mobility, but also safety, which in turn helps us achieve our goal of Zero Fatalities. Last year, Region Two completed several projects that illustrate exactly how we continue to optimize mobility through road and signal technologies.

MOBILE TECHNOLOGY

UDOT Traffic

Screen shot of UDOT Traffic app
UDOT Traffic is the department’s portal for statewide traffic information and can be accessed through the UDOT Traffic website or via mobile application for iOS or Android devices. Citizens can use the site to view real-time traffic conditions, construction and emergency alerts, road weather forecasts, and current lane and ramp closures. New to the UDOT Traffic app is a map layer that displays designated bike routes across the state, and state roads with shoulders wider than four feet. The map also displays routes that are restricted to bicycles such as I-15 in the Salt Lake Valley.

UDOT continually upgrades the UDOT Traffic portal to make it even more useful for drivers and the public. This year, the Lane Closure tool will be used for all projects on interstates as well as major highways including Bangerter Highway, Legacy Parkway, S.R. 201, and U.S. 40.

Future updates will improve integration between construction projects and the Lane Closure tool, and will allow contractors and department employees to make changes to UDOT Traffic information using mobile devices.

Citizen Reporter

Screen shots of the citizen reporting app
UDOT Citizen Reporter is a mobile application that enlists volunteers to report on current weather conditions for specific roads across Utah. This app is designed to provide both TOC operators and travelers with more accurate and timely road, weather and travel impact information and forecasts.

To participate as citizen reporters, members of the public are required to take a short course (either online or in person), complete a quiz, and then submit a sign-up form. Once those steps are completed, the volunteer receives a login and password, and can then download the app and begin submitting reports.

Citizen reporters are able to confirm weather data received through other sources (Road Weather Information Systems, meteorological forecasts, etc.) and can provide data for roadways where RWIS systems or other information sources may not be available.

ROAD & SIGNAL TECHNOLOGY

Variable Speed Limit

Photo of Variable Speed Limit sign with a semi passing by on I-80 in Parley's Canyon

Variable Speed Limit sign on I-80 in Parley’s Canyon

In January 2014, 15 new variable speed limit (VSL) signs were activated along I-80 in Parleys Canyon. The new signs are controlled by the TOC to help maintain consistent traffic flows and assist drivers in adjusting speeds when necessary due to weather conditions.

The TOC monitors speed limits in the canyon. In the event of poor weather or low visibility, a traffic engineer reviews information, such as current road conditions, weather forecasts, snowfall rates, observed speeds, and reports from maintenance personnel. Based on this information, the engineer can make the decision to reduce the speed limit as needed. Speed limits typically range from 35 to 65 miles per hour depending on conditions.

The new VSL signs are the first of their kind in Utah. UDOT is also considering installing variable speed limit signs in other locations around the state, such as Provo Canyon and Sardine Canyon, based on the results of this project.

Bike Detection

Photo of open signal cabinet
Last year, Region Two and the TOC worked together to develop and install reliable bicycle detection at nine signalized intersections in Salt Lake City, along with new pavement markings to show bicyclists where to stop. Often, bicyclists stop at red lights, look to see if they feel it is safe to cross, and then proceed through the intersection without waiting for a green signal; these upgraded intersections help encourage cyclists to obey traffic signals.

Additionally, upgrading bicycle detection systems encourages cycling as a viable means of transportation. This helps improve air quality by reducing automobile emissions, and is an asset for local economic development since many companies have reported that Utah’s alternative transportation options (such as bicycling and mass transit) were a significant factor in their decision to come to the state.

Moving forward, the department is working with the bicycling community to identify additional high-priority intersections where this detection technology can be installed.

HAWK Crossings

Photo of HAWK signal with traffic flowing underneath

HAWK

HAWK (High Intensity Activated CrosswalK) crossings have been installed in a number of locations in Region Two where arterial streets intersect with minor streets. These crossings include pavement markings, signs, and red and yellow lights on an arm over the roadway.

When a pedestrian pushes the button to activate the signal, the lights over the roadway begin flashing yellow, alerting drivers to slow down. A solid red light then activates, along with a “walk” sign for the pedestrian. Once the “walk” phase is complete, the light flashes red, indicating to drivers to treat the intersection as a stop sign – they may proceed if the crosswalk is clear. When the lights are off, drivers are not required to stop at the crosswalk.

These signals are in use at several locations throughout the Region where large numbers of pedestrians cross major roadways. UDOT continues to evaluate other locations for these signals and will install them as needed.

UDOT Traffic Operations Center celebrates its 15 year anniversary

Map image showing the Salt Lake Valley with colors indicating how CommuterLink would expand through 2002

The original expansion plan for the UDOT CommuterLink system (now known as “UDOT Traffic”)

April 27, 2014 marked the 15 year anniversary of the UDOT Traffic Operations Center (TOC) opening its doors. The UDOT TOC was built to manage congestion and traffic during the 2002 Olympics. While managing traffic for this important special event was a catalyst for building the TOC, UDOT fully understood that there would be significant benefits to operating the TOC long term.

As Utah continues to grow, so does the challenge of mobility. To address Utah’s transportation challenges, the Utah Senate passed a Senate Bill in 1995 and established a Traffic Management Committee which consisted of representatives from Salt Lake City, Wasatch Front Regional Council, Mountainland Association of Governments, Salt Lake County, the Department of Public Safety and the Utah Department of Environmental Quality. This committee recognized the benefits of a Traffic Operations Center to manage traffic and improve roadway efficiency.  The Utah Transit Authority and Federal Highway Administration also partnered with the committee. The committee determined that a TOC was necessary and shortly after, planning started on where the TOC would be built, what components it would have and how the information would be distributed to the public.  A common ITS architecture was established, which now allows all Utah jurisdictions with ITS devices to share resources.

Screen shot of a map of Utah from the UDOT Traffic website. The map has several images on it indicating the location of traffic cameras and variable message signs.

The UDOT Traffic network today. Each blue icon is one traffic camera and every yellow or black rectangle is a VMS. There are also congestion, construction and weather layers available on the UDOT Traffic app and website.

When the doors opened in 1999, the TOC was staffed Monday – Friday 5:00 a.m. – 11:00 p.m. and covered a limited number of routes on the Wasatch Front. Utah’s ITS system was given the name “CommuterLink” because it was largely commuter-centric traveler information and congestion management for Salt Lake City. Today, the TOC is staffed 24/7/365 and manages traffic statewide. To reflect the statewide approach, the system is now known as “UDOT Traffic”.

Over the years, the TOC has grown its traffic management capabilities and has added extra equipment to keep up with Utah’s transportation demands. In 1999, UDOT had deployed 150 traffic cameras and 57 Variable Message Signs (VMS). Today, UDOT has a sophisticated statewide network that includes over 900 traffic cameras and over 150 VMS! These valuable tools can be viewed on the UDOT Traffic smartphone app and website. Traffic camera images are also shared with the media and can help commuters make travel decisions while watching the morning news. UDOT’s fiber optic network is also robust – with over 1800 miles of fiber optic cable deployed, UDOT has one of the most complete and useful fiber optic networks in the nation. This network helps to establish lightning-fast communications with traffic signals, VMS, traffic detectors and other equipment throughout the state. From the TOC, UDOT can manually operate over 85% of the traffic signals throughout the state… as far away as St. George, Moab, Vernal and Logan!

Table showing the number of Traffic Cameras in 1999 as 150 and today as over 900, number of variable message signs in 1999 as 57 and today as over 150, number of traffic signals in 1999 as 550 and today as over 1400, number of fiber optic communcations in 1999 as 298 and today as over 1800 and the area of focus in 1999 as the Wasatch Front and for today it is statewide.

The UDOT Traffic Operations Center has deployed a statewide traffic management network.

From its first years of operation, the TOC has proven its effectiveness. The system has helped to increase peak-hour freeway speeds, reduce freeway delays and improve traffic signal efficiency. Traffic management is an important component of a healthy transportation network. UDOT’s TOC supports other UDOT divisions to successfully build, maintain and operate Utah’s highways. UDOT’s TOC also helps to support UDOT’s Strategic Goals: Preserve Infrastructure, Zero Fatalities, Strengthen the Economy and Optimize Mobility.

For a tour of the TOC or for more information, visit www.udottraffic.utah.gov.

Photo of the grand opening celebration with dignitaries preparing to cut a cake.

UDOT TOC Grand Opening – April 27, 1999

 

Photo of the TOC building under construction with scaffolding surrounding a brick structure.

The UDOT TOC building under construction

 

UDOT and UHP host a Traffic Incident Management Workshop

Graphic outlining Traffic Incident Management BenefitsThree injury crashes occur every minute in the United States, putting nearly 39,000 incident responders potentially in harm’s way every day. Congestion from these incidents often generates secondary crashes, further increasing traveler delay and frustration. The longer incident responders remain at the scene, the greater the risk they, and the traveling public, face.

Photo of TIM Training group with Colonel Daniel Fuhr in front addressing the group.

UHP Colonel Daniel Fuhr giving welcoming class participants.

To minimize delay and improve responder safety, UDOT and UHP hosted a Traffic Incident Management (TIM) workshop on April 9 – 10 in Salt Lake City. Participants from UHP, Unified Fire, Unified Police, UDOT, trucking companies, the St. George Police Department and other agencies were in attendance. UHP Colonel Daniel Fuhr and UDOT Traffic Management Division Director Rob Clayton welcomed the participants with information on crash statistics, our responsibility to the public, and the importance of protecting first responders from harm.

Photo of TIM Training table top exercise on scene management

TIM Training attendees participated in a table-top exercise on scene management.

The National TIM Responder Train-the-Trainer (TtT) program provided participants the knowledge and materials necessary for them to conduct TIM training for TIM responders in their area. The TtT is a 1½-day course that covers the fundamentals of Traffic Incident Management, safe crash scene set-up, quick incident clearance and on-scene coordination.

Participants were able to learn from course instructors who were former first responders. Participants were also able to participate in a tabletop exercise as well as learn about proper accident scene set-up.

Traffic incidents, including crashes, disabled vehicles and debris on the road create unsafe driving conditions, put motorists and responders at risk, and account for approximately 25 percent of all traffic delays.

Photo of Incident Managment truck with compartments open so Supervisor Jeff Reynolds can show what is in them.

UDOT’s Incident Management Team Supervisor Jeff Reynolds showing TIM class participants the equipment on his vehicle during the outdoor scene setup exercise.

For each minute that a freeway travel lane is blocked during peak use, an estimated 4 minutes of delay result after the incident is cleared. This estimate accounts for 4.2 billion hours per year in delays. Additionally, the U.S. Department of Transportation reports that Americans burn more than 2.8 billion gallons of gasoline every year while stuck in incident-related traffic. TIM Training can give us the tools to clear incidents more quickly, saving time, money and lives. More information can be found on the National Unified Goal for Traffic Incident Management website.

The training was made possible through a Federal Highway Administration Strategic Highway Research Program.

Little Cottonwood Communcation Tool Silver Barrel Awards

Recently Alta Mayor Tom Pollard reached out to Executive Director Carlos Braceras to express his appreciation for the Little Cottonwood Communication Tool. This tool was developed by the Traffic Operations Center and allows the Alta Marshal and other designated individuals to deliver impact and closure details regarding the road through Little Cottonwood Canyon.

“Our Marshal’s department has initiated over 160 alerts using this technology and has experienced a marked and meaningful improvement in the delivery of information related to the safety and efficient traffic flow for motorists using S.R. 210,” Mayor Pollard explained in a letter to Carlos.

UDOT leadership expressed their gratitude by presenting silver barrel awards to those involved with the project. Award recipients included:

Rob Clayton
Chuck Felice
Liam Fitzgerald
Paul Jencks
Robert Miles
Lisa Miller
Lee Nitchman
Brady Roberts

Variable Speed Limit Signs Now Activated on I-80

Photo of Variable Speed Limit sign with a semi passing by on I-80 in Parley's Canyon

Variable Speed Limit sign on I-80 in Parley’s Canyon

The UDOT Traffic Operations Center (TOC) now has a new tool to enhance safety for drivers  on I-80 – one of the most heavily-traveled roads in the state. Last Wednesday (Jan. 8), 15 new variable speed limit (VSL) signs were activated along I-80 in Parley’s Canyon. The new signs will be controlled by the TOC to help maintain consistent traffic flows and assist drivers in adjusting speeds when necessary due to weather conditions.

The 15 signs – 8 eastbound and 7 westbound, located between the mouth of the canyon and Jeremy Ranch, are equipped with LED display screens that allow UDOT to remotely adjust speeds. These adjustments will be made based on driver behavior and road conditions.

“We are always looking for new technologies to help us manage traffic more effectively and enhance safety,” said UDOT Region 2 East District Engineer Robert Miles. “These signs will help keep drivers moving and reduce the number of weather-related crashes in Parley’s Canyon.”

The variable speed limit signs in Parley’s Canyon have been divided into four zones – an eastbound lower zone and westbound lower zone, from the mouth of the canyon to Mountain Dell/Lambs Canyon, and an eastbound upper zone and westbound upper zone, from Mountain Dell/Lambs Canyon to Kimball Junction. When a speed limit is adjusted for a specific zone, the new speed limit will be displayed on all signs within the same zone. These zones were created because of the differences in weather patterns and average speeds observed in the canyon due to changes in elevation.

The TOC will monitor speed limits in the canyon. In the event of poor weather or low visibility, a traffic engineer will be able to review information such as current road conditions, weather forecasts, snowfall rates, observed speeds, and reports from maintenance personnel. Based on this information, the engineer can make the decision to reduce the speed limit as needed. Depending on conditions, speed limits may range from 35 to 65 miles per hour.

The new variable speed limit signs are the first of their kind in Utah. Other states, including Washington, Wyoming, Colorado and Nevada, currently use these signs and have observed a reduction in weather-related crashes in areas where these signs are employed. Washington (Snoqualmie Pass – I-90) and Wyoming (east of Evanston – I-80) in particular are using these signs in areas similar to Parley’s Canyon: interstate highways with moderate to heavy traffic, with significant elevation differences, that are prone to inclement weather.

The Parley’s Canyon VSL project was developed jointly by UDOT and the Utah Highway Patrol (UHP). The speed limits posted on these signs are not merely advisory speeds, but regulatory speed limits that will be enforced by UHP troopers.

I-80 in Parley’s Canyon was selected as the location for this pilot project due to its changing weather conditions, heavy traffic, and existing fiber optic communications network. The investment for the design and construction for the new signs was $750,000, and the annual operating expense is estimated between $7,500 and $10,000. UDOT is also considering installing variable speed limit signs in other locations around the state, such as Sardine Canyon and Provo Canyon, based on the results of this project.

This guest post was written by Aaron Mentzer with the UDOT Traffic team.