A composite metric for mobility is based on key performance measures. The individual criteria are weighted as follows:
• Reliability (35%)
• Snow and ice removal (24%)
• Delay (30%)
• Mode Split (11%)
How are we doing?
Historical data for our optimize mobility goal is limited in comparison to the other two strategic goals. We have fewer years of available data and the information displayed is limited to I-15 along the Wasatch Front.
Previously, delay data was expensive and difficult to collect. With new technologies, greater volumes and accuracy of data are available across the system. Reliability is an emerging performance measure nationally, and we have established new measures for mode split and snow and ice removal. We are in the process of establishing baseline data for this index.
UDOT uses a broad array of strategies to enhance mobility and mitigate congestion through:
• Strategic capacity improvements
• Efficient operations
• Enable travel choices
Strategies in these areas come from groups and regions across the department including program development, project development, and operations.
Strategic Capacity Improvements
Through a data driven prioritization process, capacity projects are selected that add new lanes or roads to the state’s roadway system. Improvements can include major capacity projects and chokepoint projects. Click here to learn more about these projects on an interactive map and how we prioritize them.
Utah leads the nation in terms of connected signals with 88 percent of signals throughout the state connected to one shared system managed at UDOT's Traffic Operations Center (TOC). This allows us to be more responsive and operate a more optimize traffic system.
UDOT engineers have also developed adaptive signals to adjust cycle length types to accommodate motorist and pedestrian traffic.
The Incident Management Program’s goal is to increase first responder safety, improve reliability, and reduce delay and secondary crashes. Activities include assisting stranded motorists, removing debris and providing traffic control at crash scenes.
We use multiple channels to inform travelers of potential impacts and delays as well as share safety messages to improve mobility on our roadways.
- Variable Message Signs (VMS): Statewide research consistently shows Utah drivers consider VMS information to be their top resource for information such as expected travel times, upcoming construction, weather conditions and lane closures. UDOT has received positive public and media response for increased use of VMS for public safety campaigns including seat belt awareness, air quality initiatives and drunk driving enforcement.
- UDOT Traffic: This website and app provide access to information about traffic conditions, accidents, road construction activities, seasonal road closures, traffic cameras and VMS messages. The UDOT Traffic app has a push-alert feature, called the TravelWise Alert, to inform the traveling public of major traffic issues.
Snow and Ice Removal
When winter storms occur, the public, businesses, and the economy are dependent on clear roads to safely travel to their destinations. We operate a fleet of over 500 snowplows to manage an average of 25 winter storms and remove more than 65 million tons of snow and ice on Utah’s roads. UDOT continues to make the snow and ice removal process more efficient by:
- Using technology such as Road Weather Information Systems (RWIS) and weather forecasting information to assess conditions and strategically dispatch plows
- Applying brine before storms and using salt more efficiently
- Using equipment such as wing plows and tow plows that allow greater efficiency
- Saving more than 20,000 gallons of diesel fuel per year by training drivers on proper acceleration, deceleration, idle reduction and travel speeds using a snowplow simulator
- Pre-wetting the salt with a brine or other liquid to kick startthe melting process saving the department 18,000 tons of salt annually
- LED lights on wing plows to increase visibility by traveling public
Enable Travel Choices
Offering alternative modes of transportation will improve mobility on roadways and extend the life of our assets. By working with our community partners, we encourage and facilitate the development of an integrated transportation system that fit community, environmental, economic and transportation conditions. The Travelwise program encourages residents to rethink the way they travel to reduce congestion on roadways. Actions such as shifting travel times to avoid primary commute periods, taking transit, or combining errands also known as trip chaining.
Mobility Performance Measures
UDOT is focused on optimizing mobility by tracking performance measures for delay, reliability and mode split. Today, these measurements are for I-15 in urbanized areas and our goal is to show these on a system basis in the future. Our targets for the following measures are:
- Delay: Meet projected annual delay increase of 3 percent or better
- Reliability: 80 percent of one mile segments on I-15 to be considered reliable
- Mode Split: 10 percent of all trips be on transit
- Snow and Ice Removal: Less than 7.5 percent of snow removal efforts rated unacceptable
Delay - Monthly
Delay is defined as the additional travel time experienced by a driver, passenger or pedestrian, due to circumstances that impede the desirable movement of traffic such as bottlenecks, car accidents or weather conditions. It is measured as the time difference between congested travel time, the travel time at 50 mph, which is the optimal speed to maximize traffic flow. The monthly target is established by dividing the projected annual delay by 12.
This score is determined using the BTI and comparing it with a threshold of 0.6. The two reliability categories listed in the graph are determined by comparing the average speed of vehicles (50 mph) and extra time required for travelers to ensure on-time arrival 95 percent of the time, also known as Buffer Time Index (BTI).
The graph below shows person trips from current volumes and UTA ridership in the 2016 I-15 corridor during PM peak period.
Snow and Ice Removal - Current Year
The pie chart to the right shows how effectively UDOT was able to remove snow and ice from roadways around the state.
Additional information on current road conditions can be found on the UDOT Traffic Website.
Snow and Ice Removal - Past Two Winters
The bar chart to the left compares snow and ice removal on a month by month basis since November 2016.