Sept. 8, 2014

Iowa DOT assists maintenance personnel on the go

These days the Iowa Department of Transportation talks a lot about dashboards, especially when it comes to our maintenance operations. With more than 900 snowplows, that is a lot of actual dashboards—but the ones we talk the most about can be viewed on a desktop, laptop, tablet or other mobile electronic devices.

The Iowa DOT’s 109 garages employ approximately 1,000 permanent winter staff. These folks are charged to care for 9,480 centerline miles and 24,200 total lane-miles in three different winter-service-level classifications. During harsh Iowa winters, keeping traffic moving on all those roads typically takes 166,000 tons of salt, some of which is mixed into 16 million gal of salt brine.

Tina Greenfield, Iowa DOT weather coordinator, said, “Costs, performance and customer expectations are always tricky issues to manage in highway maintenance. At the Iowa DOT, we set out to find a better way to estimate and control the cost of salt and labor, while maintaining a high service level for travelers. We have developed five dashboard innovations to assist managers in decision making:

  • Salt/labor management dashboard;
  • Expected salt forecast dashboard;
  • Traffic-speed-based performance dashboard;
  • Public-facing performance dashboard; and
  • iPhone plow cameras (mounted on actual truck dashboards).”

In addition, all Iowa DOT snowplows are equipped with global positioning systems (GPS) and automatic vehicle location (AVL) systems. This allows data such as liquid- and solid-chemical application rates, plow status, air and pavement temperatures and vehicle location to be automatically fed back to the relevant databases.

Salt/labor management dashboard
Through years of experience, the 53 highway-maintenance supervisors who oversee Iowa’s 109 garages each have a little different strategy of what works in their specific service area. While winter weather, topography and other factors are to be considered, the Iowa DOT needed a consistent way to manage salt use and labor hours. In 2011, Greenfield and the staff of the Iowa DOT’s information technology group began working on a solution.

“Development of this dashboard tool began because supervisors needed a better way to track salt use and to see how each garage’s salt supply is being utilized on an ongoing basis,” said Greenfield. “Since each garage has slightly different winter storms than their neighbors, and since each garage has a unique number of miles and mix of road-service levels, it is tempting but misleading to simply compare resource use from garage A to garage B. You have to account for weather and responsibility area first.”

The DOT’s policies contain a chart relating weather observations to a suggested salt application rate and guidance on application modifications to the different service levels. We used this chart to create a program that estimates an expected salt or labor amount used in a recent storm for each garage based on its responsibility-area characteristics and its local weather information. This estimate is now a good benchmark of comparison for their actual use.

These comparisons flow into an online interactive reporting system available to Iowa DOT maintenance supervisors, allowing them to more closely monitor salt use and staff time. “Using the elements of the dashboard, a maintenance supervisor can see at a glance the salt use of each garage and how it compares with the expected use based on our policies,” said Greenfield. “But real life is never quite as simple as a formula. The supervisors all have to use their experience in conjunction with the data to make the best decisions to maintain an adequate level of service using the least amount of resources.”

Each garage has a budget for the winter season plus an estimation of a season’s salt use based on past years’ weather data. The salt supply, targets and use are constantly monitored. Greenfield said by closely tracking salt use, the Iowa DOT has seen more consistent use across the state. “It has also led to better recordkeeping—a simple reporting error is now easy to spot because it will not be consistent with the day’s estimated use.”

Expected salt forecast dashboard
The second dashboard, the expected salt forecast, is closely tied to the salt/labor management tool. This dashboard creates an expected future salt use for an upcoming storm based on forecast weather data provided by our weather-forecast contractor. This expected salt use allows supervisors to plan ahead for material needs. And if during a storm the actual use is starting to deviate, they can make corrections before it gets out of hand.

Traffic-speed-based performance dashboard
The Iowa DOT has just begun experimenting with the third dashboard in their toolbox. “We have previously not used traffic speed as a performance goal for winter maintenance,” said Greenfield. “But using traffic speed for this purpose is attractive, since it is relatively easy to measure.”

This forthcoming dashboard creates an expected in-storm traffic speed based on the weather conditions at the time and then compares the actual speed to the expected speed. The difference between estimate and actual speed is a measurement of our performance. If we can keep traffic moving faster than expected, then we assume we are performing well, given the weather conditions. In the other case, we assume that something has gone wrong.

“The estimation of traffic speed serves an important purpose,” explained Greenfield. “It is to account for variations in weather from place to place or season to season. In a terrible blizzard, you would expect traffic to go slowly even under your best effort, while in a light flurry the expectation would be very near normal speeds. Which of these weather scenarios you are dealt is not in your control. But how well you meet expected speed is.”

Public-facing performance dashboard
The Iowa DOT has created some great tools for employees to use. The next logical step is to improve the way the agency communicates how and why operations are carried out as they are. The Iowa DOT’s fourth dashboard project is a public-facing website to allow anyone to see how well we are serving them.

This dashboard includes various weather, use and cost information that is updated every two weeks. Various graphs and metrics give the public an idea of the current salt capacity, historic costs of materials, equipment and labor for each year and other aspects of maintenance activities.

Dashboard cameras
Managing maintenance activities during an Iowa winter can be challenging. Garage supervisors cannot be everywhere all of the time. Even more challenging is helping travelers make better, safer choices. Iowa has a robust 5-1-1 traveler information system, but when the road condition on 5-1-1 is listed as “partially covered,” what does that look like? Dashboard-mounted cameras (iPhones) in snowplows now let maintenance managers and the public see what the plow drivers see out on the roads during winter weather.

“When we were first exploring the idea of putting cameras in snowplows, we wanted to make sure that this would not add any distraction to our drivers that would jeopardize their safety,” said John Hart of the Iowa DOT Office of Maintenance. “We explored several options and decided to use an iPhone 4 mounted to the windshield of the snowplow. Our own staff in the Information Technology Division were able to develop an app for the iPhone that allows the still camera function to operate automatically, so there is no extra work or distraction for our drivers.”

The first 200 iPhones were installed in late 2013 and early 2014. Another 200 will be installed for the 2014-15 winter season. They are programmed to take still shots every 10 minutes. The images are geotagged and automatically sent back to a website where they can be viewed by clicking an icon on a map. The images only stay on the site for a limited time.

Hart said, “The photos are available on a publicly available snowplow-map website, which shows various aspects of our operation, including snowplow location, material use and other data. The camera images are another layer of data added to this system that has already proven to be very valuable in making decisions that keep our highways safer.”

In addition to the five dashboard projects, the Iowa DOT has several other winter-maintenance projects under way:

Salt-spreader evaluations
It might seem obvious, but there is one goal when spreading salt: Make sure it lands on the road, where it is useful. Accomplishing this is a balance of truck speed, spreader type and prewetting the salt with brine. The Iowa DOT has been conducting research to develop an understanding about which combination of factors yields the best result.

Six different types of spreaders were tested at two different speeds and five different prewet rates. A measurement of each of the 60 possible combinations was made by collecting the salt deposited on a test grid.

This evaluation is helping the Iowa DOT choose the most cost-effective equipment and prewet practices and also may benefit the environment by reducing the amount of salt that immediately bounces into the ditch.

Nontraditional RWIS stations

Roadway weather information systems (RWIS) are a great way to collect data. They also can be very expensive and complicated. Greenfield said, “We needed to find a cost-effective solution to the gaps in weather data. We talked to the field folks and found out what types of information were most critical to their operations and then researched the best way to get them that data. What we found was a scaled-back weather station that provides the basic atmospheric conditions at a fraction of the cost of a larger RWIS unit. The smaller units can’t provide precipitation data or support speed sensors or cameras,” said Greenfield. “But they can provide the basic weather information garages need, like pavement temperature and wind speed and direction.”

Greenfield said, “There are a lot of benefits with the smaller stations. They install very easily and are basically ‘plug and play.’ Our employees can install them instead of having to hire a contractor like we do for the large RWIS units. The smaller stations use radio communications, so there is no charge for cellular connections like the large stations. In the garages, the radio unit receiving the data from the weather station can plug directly into an Ethernet jack, so data can be automatically fed to a web page.”

Some innovations like the salt dashboards and mini-RWIS have already transformed our operations and have become part of our day-to-day world, while others, like the traffic-speed dashboard, will just be making their first appearance. What impact it will have on our operations is yet to be seen. One thing is for sure, though: There will always be a better way and it is in our best interest to keep searching it out. R&B

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