What Is MDSS?
Why Use MDSS?
An MDSS can*:
- Provide route-specific weather and road condition forecasts
- Offer optimized recommendations for application times and chemical types and amounts
- Generate "what if?" scenarios to experiment with changes to the recommended treatment strategy
- Train new maintenance supervisors using the customized rules of practice and historical playback capabilities
Winter maintenance is complex. In order to provide safe and clear roadways, maintenance managers must be able to handle multiple tasks and process a great deal of information effectively and wisely. But conflicting weather forecasts, unreliable road condition reports, and the variable effectiveness of roadway treatments make winter road maintenance particularly difficult.
A Maintenance Decision Support System (MDSS) can help maintenance personnel manage this information, thereby improving roadway levels of service and safety, reducing impacts on the environment, and being more efficient in the use of labor, equipment, and chemicals.
MDSS can benefit state and local departments of transportation (DOTs) in many ways. Some benefits include:
- Reducing costs of labor, materials, and equipment
- Improving public safety
- Improving mobility
- Realizing a higher level of service on roads
- Maintaining consistency of service across districts or states
- Reducing impacts on the environment
- Providing training for both new and experienced DOT personnel
- Providing a "one-stop" location for weather and pavement treatment information
- Enhancing collaboration between DOT maintenance areas
- Providing a way to review maintenance actions during past storms
- Better staging of equipment during pre-storm preparations
- Ability to better allocate shift personnel
- Making more informed decisions about the effectiveness of chemicals before, during and in the post-storm environment
MDSS Background
The Federal Highway Administration (FHWA) defines MDSS as "a decision support tool that integrates relevant road weather forecasts, coded maintenance rules of practice, and maintenance resource data to provide winter maintenance managers with recommended road treatment strategies."[2] A decision support system uses data and models to evaluate different options, helping to guide a person in decisions about a given problem (in this case, winter maintenance operations).
MDSS improves upon existing forecasting and expert systems by providing optimized treatment recommendations. Advanced forecast systems provide specific weather and road condition forecasts, but do not provide snow and ice treatment recommendations. Likewise, expert systems, which rely on logic designed to mimic decisions of experts in the field, are constrained by the conditions that are input into the system at the outset. MDSS is a decision support system – helping maintenance professionals with recommendations that make roads clearer and safer under many scenarios.
How MDSS Developed
In 1999, the FHWA Road Weather Management Program initiated The Surface Transportation Weather Decision Support Requirements Project. This project combined the capabilities of six national laboratories, State DOTs, the private sector, and academia into a collaborative stakeholder group. Under the group's guidance, the laboratories integrated state-of-the-art weather forecasting capabilities with computerized winter maintenance rules of practice, resulting in the federal MDSS functional prototype. This prototype underwent several developmental cycles and several seasons of field demonstrations and evaluations.
In 2002, a Pooled Fund Study was initiated to develop, implement, and deploy an operational version of MDSS. The study focused upon refinement, validation, and wide-scale deployment of sustainable decision support technologies. By 2004, MDSS technologies were mature enough for interested private sector companies to begin to incorporate MDSS features into their product lines and to begin to provide services to DOTs. Today, there are several companies that provide various levels of MDSS capabilities within their product lines. Information about MDSS is available at the National Center for Atmospheric Research's web site.[3] Vendor contact information is available from the FHWA web site.[4]
What MDSS Does
MDSS is a tool designed to support snow and ice control operations along specific road segments. MDSS is based on leading diagnostic and predictive weather research capabilities, road condition formulas, and rules of practice for anti-icing and deicing. MDSS generates information and recommendations based on predicted:
- Pavement temperature
- Pavement condition (e.g., pavement friction and snow accumulation)
- Weather impacts
- Air temperature
- Wind and gusts
- Relative humidity and dewpoint
- Precipitation (type, intensity, and amount)
- Pavement/bridge frost potential
- Blowing snow potential
- Treatment recommendations
- Recommended treatment plan (such as plow only, chemical use, and prewetting)
- Recommended chemical application amount
- Timing of initial and subsequent treatments
- Indication of the need to pre-treat or post-treat the roads
MDSS can be used for strategic planning 12–48 hours in advance of a storm, so personnel, material, and equipment resources are ready.
MDSS also enables personnel to make tactical decisions and manage their resources just prior to and during a storm (0–12 hours). For example, if a storm has passed a district and is approaching another district, the maintenance managers can move resources accordingly. Previously, weather and road condition information have not been well-organized and integrated, making it difficult for maintenance crews to decide which actions to take.
With the development of MDSS, maintenance personnel have a 'one stop shop' that provides weather and pavement forecasts, and treatment recommendations within a single application.
MDSS technologies can provide two-way communication links between the maintenance supervisors and trucks using mobile data communication and automated vehicle location technology. This includes equipping snowplows with global positioning system devices that are capable of obtaining and reporting weather conditions and equipment status as the trucks move along their routes. The goal is to obtain, in near real-time, the location of each truck, the plow blade position, the chemical type and application rate, along with air and road temperatures and pavement conditions.
(Photo courtesy of the Washington State Department of Transportation)
Weather forecast models generally do a good job providing forecast information for large-scale events, such as frontal systems and winter storms. However, for short-lived or small-scale events the models may have difficulty in providing accurate forecasts. In such cases, MDSS users must use radar data, weather observations, experience, and other tools to monitor conditions and use the MDSS output effectively.
Commercial road weather service providers (commercial providers) offer MDSS that may include all or part of the functionality mentioned above. These systems provide a range of integrated weather and road condition forecasts that enable trucks to communicate with the central MDSS.
Commercial providers offer various approaches to MDSS. One approach is a web-hosted solution where software is operated at the commercial provider's site with agency access provided by the Internet. Another approach is a hosted client/server where part of the application operates on agency computers, but other parts run on a central server, typically web-hosted, at a commercial provider's site. A third alternative is for the agency to have the application completely installed and operated at its sites.
Agencies may also choose to develop their own applications.
The overall flow of the functional prototype MDSS is shown in the following exhibit. Commercial products based upon the prototype have a similar structure; products not based upon the prototype may differ in structure but have similar functions.
Data input for the MDSS prototype includes meteorological and road observations and output from weather prediction models. This includes surface meteorological observations from National Weather Service and Federal Aviation Administration airport sites. These systems are updated at least once per hour. Input also includes both atmospheric and pavement data from DOT environmental sensor stations. Many of these stations have sensors to measure atmospheric, pavement, and water level conditions along roads. In some cases, data can be transmitted from maintenance vehicles regarding their locations and treatment activities and input to the MDSS.
All of the input data are then forwarded to the Road Weather Forecast System. This system has formulas that synthesize the information to create a forecast that contains all of the elements that are needed to begin treatment recommendation generation. Elements include: forecasted air temperatures, precipitation types and their probabilities, and wind speeds.
The Road Condition and Treatment Module takes the forecasted weather elements and uses a computer model to predict road conditions (e.g., snow depth and pavement temperature). This model also generates recommended treatments and gauges the effectiveness of those treatments.
Once maintenance professionals settle on a treatment plan, MDSS presents recommendations in a user view in graphic, map, and narrative form. From here, users can view specific roads and weather parameters. The MDSS recommendations can be customized based on agency-defined policies and by capturing the knowledge of experienced staff. For example, agency policy may restrict the application of certain chemicals on specific routes due to environmental concerns. Such restrictions can be reflected in treatment plans. If an agency is using mobile data communications/automated vehicle location, treatment recommendations can be sent directly to an operator in a truck in some vendor systems.
In some implementations of MDSS, the system can generate "what if?" scenarios. This capability allows a maintenance manager to modify the timing, chemical type, or application rate on any of the routes to see how the changes might affect the treatments or forecasted road conditions.
The exhibits that follow are prints of screens from the FHWA functional prototype. These provide an idea of how the systems look and what information they provide. It should be noted that any given commercial MDSS product will have a different presentation or may allow the agency to configure its own screens. Some of the screens available from commercial providers are based on extensive analysis of how computer users interact with systems (i.e., human factors).
Main MDSS Display Screen
(This screen is from the FHWA functional prototype. Any given commercial system will have a different appearance.)
What If Scenario
(This screen is from the FHWA functional prototype. Any given commercial system will have a different appearance.)