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Federal Highway Administration > Publications > Public Roads > Vol. 69 · No. 5 > Geospatial Technologies Improve Transportation Decisionmaking

Mar/Apr 2006
Vol. 69 · No. 5

Publication Number: FHWA-HRT-2006-003

Geospatial Technologies Improve Transportation Decisionmaking

by Lindsay Banks and Mark Sarmiento

Geographic information systems enable State DOTs to streamline tasks and projects related to operations, road routes, safety, engineering, conservation, and more.

Remote sensing and GPS use satellites similar to this one to gather data that can be used by State DOTs to improve decisionmaking and save time and money.
Remote sensing and GPS use satellites similar to this one to gather data that can be used by State DOTs to improve decisionmaking and save time and money. Photo: Lockheed Martin Corp.

Faced with the daunting task of managing the Nation's transportation system with limited resources, the work of State departments of transportation (DOTs) is driven by the need to produce quick, high-quality results without overspending. Delivering transportation projects on time without sacrificing quality requires accurate and complete data. Geographic information systems (GIS) and advanced data collection technologies such as remote sensing and global positioning systems (GPS) have helped many DOTs produce that data, enabling them to improve decisionmaking while saving time and money.

"GIS should be the tool of choice for forward-looking executivesthose who . . . want to "skate to where the puck will be,'"says Federal Highway Administration (FHWA) Associate Administrator for Planning, Environment, and Realty Cynthia J. Burbank. "GIS can improve the speed and quality of decisions, cut costs, and allow multiple teams to work together effectively. What executive isn't seeking that?"

Many State DOTs are going a step further, using the systems in conjunction with Internet technologies and the Web to distribute the information more widely and in a more cost-conscious manner. As more and more States apply GIS, and as they share their experiences with others, the benefits of using geospatial technologies can multiply.

"But it isn't going to happen without an executive-level commitment to GIS—a commitment to funding and staff for GIS, and executive-level time to figuring out what decisions could be aided by GIS applications," Burbank says.

FHWA's Role

Recognizing the potential impact that geospatial technologies can have on the work of State DOTs, FHWA has taken an active role in promoting these technologies through courses and workshops. FHWA encourages State DOTs to exchange their knowledge of geospatial technologies and their experiences with using them. In addition to providing support for GIS activities, FHWA is seeking champions to share their work with other DOTs.

A number of States have charted successes with geospatial technologies and report satisfaction with their experiences in using those technologies to improve decisionmaking and save time and money. A sampling of six States offers examples from various regions of the country: Arkansas, Delaware, Georgia, Nevada, Virginia, and Washington.

Arkansas

The Arkansas State Highway and Transportation Department (AHTD) used GIS to streamline the transportation decisionmaking and permitting process for the Southeast Arkansas I-69 Connector. GIS enabled AHTD to share and consolidate environmental and engineering data, and to refine and efficiently analyze large amounts of information on study areas. The agency also used GIS to foster coordination with resource agencies, the public, and Native American tribes early in the environmental review process while efficiently addressing review requirements. Partner agencies supported using GIS because the project steps occurred more quickly.

Mainly through the use of this technology, AHTD was able to reduce by almost 60 percent the amount of time required to move from notice of intent to record of decision. The maps and analyses that GIS investigation provided also gave partners and communities tangible examples of how various project alternatives would affect environmental, cultural, and economic resources.

Randal Looney, environmental coordinator at FHWA's Arkansas Division Office, says, "The use of GIS as a preliminary screening tool for environmental constraints has greatly accelerated the decisionmaking process for us, particularly on large-scale study areas associated with EIS [environmental impact statement] -level projects."

Robert Fuhler, the section head for GIS in AHTD's Environmental Division, also praises the technology, especially its use on the I-69 project. "Generally, the use of GIS has greatly increased efficiency and data distribution on projects," he says.

His team has been successful in providing others at AHTD with GIS training, data coordination, and method development, making for a smoother transition and improved incorporation of data within the department, he says.

In addition, with the incorporation of GPS technologies, accuracy in identifying and collecting constraint locations and their delineation has increased substantially. "Processes and procedures covering the gamut from project start to final output of analyzed data for decisionmaking increases efficiency [and] productivity, and greatly reduces redundant efforts," according to Fuhler.

Geospatial Technologies

The terms "GIS," "remote sensing," and "GPS," often are used together when discussing geospatial technology. Engineers collect data with a global positioning system (GPS) unit or using remote sensing and then integrate that data into a GIS program.

The phrase "geographic information systems" and the acronym "GIS" refer to the systems of hardware and software used to analyze, process, and store geographic data. Although GIS often is associated with producing maps, its true power lies in its ability to maximize the quality and use of spatial data with analyses to help answer questions such as where, how far, how many, what size, and within what area?

Remote sensing is the acquisition of data from a distance, usually with the use of satellite imaging, aerial photography, radar (radio detecting and ranging), lidar (light detection and ranging), sonar (sound navigation ranging), or other technologies. It allows users to obtain information about an area without sending people to that area.

GPS units operate through a satellite-based navigation system made up of a constellation of 24 satellites orbiting 19,320 kilometers (12,000 miles) above the surface of the Earth. The U.S. Department of Defense launched the system, which was originally intended for military applications but was made available for civilian use in the 1980s. There are no subscription fees or setup charges to use GPS. It works in any weather conditions, anywhere in the world, 24 hours a day.

GPS satellites circle the Earth twice daily in very precise orbits and transmit signal information to the planet's surface. GPS receivers use this information to calculate the user's exact location through triangulation. A GPS receiver must be locked on to the signal of at least three satellites to calculate a two-dimensional (2-D) position (latitude and longitude) and track movement. With four or more satellites in view, the receiver can determine the user's three dimensional (3-D) position (latitude, longitude, and altitude). Once the user's position has been determined, the GPS unit can calculate other information, such as speed, bearing, track, trip distance, distance to destination, sunrise and sunset times, and more.

Delaware

For transportation professionals at the Delaware Department of Transportation (DelDOT), GIS is a powerful, efficient tool to construct and analyze transportation networks; conduct impact assessments; and create visual representations of assets, project locations, and transportation data layers. DelDOT had adopted GIS technology in its day-to-day operations, but various limitations remained: data were maintained in several locations, and employees had to have GIS software installed on their desktops to access the data and create maps, or needed to contact DelDOT's GIS group to request data or maps.

This screen capture from one of AHTD's GIS programs features highway bridges in yellow and potential impact sites along the roadway in red. Aerial imagery also can be used to identify terrain features such as the pipeline in the northeastern quadrant and subdivision development, which is the large areas crosshatched in red.
This screen capture from one of AHTD's GIS programs features highway bridges in yellow and potential impact sites along the roadway in red. Aerial imagery also can be used to identify terrain features such as the pipeline in the northeastern quadrant and subdivision development, which is the large areas crosshatched in red.

DelDOT officials recognized that collecting information was a time-consuming obstacle to completing projects quickly and efficiently. Also, many employees needed access to spatial data but lacked the skills to navigate desktop GIS programs. In 2004 DelDOT decided to pursue a more cost-effective and user-friendly system that would accommodate its burgeoning volume of spatial data.

The agency teamed with GeoDecisions®, a Pennsylvania-based consulting firm specializing in GIS and information technology, to create an online information portal for DelDOT employees. The portal is known as the "Information Network for Online Resource Mapping" (INFORM).

"The goal was to provide optimized data dissemination in a cost-effective manner," explains Brian Smith, GeoDecisions project manager. "A Web portal provides easy data access without the need of additional client software and with little training involved."

By allowing key decisionmakers and planners access to a database of project information that is regularly updated and maintained, and with all stakeholders sharing the same information, INFORM leads to more informed decisionmaking.

"These data were available before, but they weren't easily accessible," says Don Burris, DelDOT's manager of transportation assets and engineering systems. "With INFORM, the data are found at one location, most data can be accessed with three simple mouse clicks, and everyone within DelDOT is now looking at the same dataset."

INFORM also integrates data from a variety of DelDOT business systems. Among other things, it enables employees to analyze multiple types of projects to ensure correct scheduling or to view various types of traffic information. Crash, road, bridge, transit, environmental, and basemap data features are available for analysis throughout the network. Users also can display various basemap features at one time and create multiple thematic maps based on business data.

Shown here is a screen shot of the 'INFORM' homepage. INFORM enables users to compare multiple themes from different DelDOT business areas.
Shown here is a screen shot of the "INFORM" homepage. INFORM enables users to compare multiple themes from different DelDOT business areas.

"Overall," says Burris, "the new Web application has increased productivity, improved decisionmaking, and translated into cost savings for the Delaware Department of Transportation."

Georgia

After undertaking a thorough review of day-to-day activities and general areas that could benefit from improved technology, the Georgia Department of Transportation (GDOT) decided that a GIS portal could improve the agency's business operations. The GDOT reviewers realized that GIS could not only improve existing services but also provide new services by centralizing various databases and making them accessible through an Internet portal.

Using in-house resources and personnel, GDOT created the "Transportation Explorer Information Portal" (TREX), an online GIS portal that enables the department to present information to State employees, citizens, elected representatives, and officials from FHWA. "We are now addressing a greater diversity of needs from a much larger audience than we were before," says Teague Buchanan, GDOT's GIS manager.

To meet the rapidly increasing demand for maps and spatially enabled data, GDOT wanted to make this information readily available to anyone who may need it. Due to the powerful capabilities of GDOT's ArcIMS®/ArcGIS® server, users can access information about current projects, review plan details, view photos, and look at contract details—all with the click of a button.

This screen shot shows railroad crossing images that have been saved within the INFORM database for display. Users click on the railcrossing layer and select the crossing of their choice, where they can then view pictures of that crossing from all four directions.
This screen shot shows railroad crossing images that have been saved within the INFORM database for display. Users click on the railcrossing layer and select the crossing of their choice, where they can then view pictures of that crossing from all four directions.

"Fulfilling information needs is more effective than teaching everyone to be a GIS user," Buchanan says. "Web-based GIS helped us simplify the end-user experience." Unlike other static Internet maps, this system enables the user to interact with the data, selecting and finding features by attributes. Easy access to data makes the project development process more inclusive and helps organize the management of projects.

GDOT has reported significant improvement in the delivery of services and information. Some tasks that formerly required hours or even days of information gathering now take only minutes. While increasing the timeliness of response to data inquiries, GDOT also was able to decrease the cost of responding. Additionally, agency officials have noted an increase in the amount of citizen participation. The program is easy to use and can be accessed from the comfort of private homes. The considerable amount of information available publicly has increased the transparency of GDOT's work, which could result in an increase in public trust.

"Our greatest satisfaction is watching people use our application in their day-to-day business," says Buchanan. "It's very gratifying to know that our application is providing a valued service to the public and our transportation partners."

This graph illustrates the rising use and popularity of TREX within GDOT over just a 5-month period in 2005, with the number of files accessed standing at 137,000 in January, rocketing to 448,000 in February, rising to 694,000 in March, nearly steady at 660,000 in April, and growing further to 750,000 in May.
This graph illustrates the rising use and popularity of TREX within GDOT over just a 5-month period in 2005. Source: GDOT.

TREX recently won a Best of Georgia Award in the category of redefining government. The award, created by the Government Technology Conference (GTC) with Governor Sonny Perdue and the Commission for a New Georgia, is presented to the agency or organization "that has adopted the best practices already being utilized by the private sector wherever appropriate to make State government function as productively, effectively, and as efficiently as possible," according to GTC.

Nevada

The Nevada Department of Transportation (NDOT) built a transportation GIS that merges crash data with a roadway basemap and relates the two. NDOT compiled partial datasets from several State and local offices into a single, consistent basemap in a new database, converting the data regardless of its native format. The new, geospatially enhanced Safety Management System (SMS) also stores and retrieves all of the various linear referencing methods used by police to locate crash sites, including intersection offsets, milepost offsets, and address matching. Dynamic segmentation capabilities that correctly maintain the relationships between roads and their crash attributes also are incorporated in the new system.

With SMS, NDOT staff can perform the following additional applications:

  • Corridor analysis to examine crashes occurring within certain given proximities of intersections
  • Midblock analysis to track crashes occurring away from intersections
  • Dataset merges to facilitate identifying relationships between crashes and other factors such as pavement conditions

Practically, NDOT's use of GIS technology means that it can better coordinate with other authorities and field staff to improve highway safety, says Chuck Reider, principal safety engineer for NDOT. "GIS technology can display information in a way that's much more intuitive and easy to understand." Tables, spreadsheets, and the like are easily usable by some, especially experts and professionals, but graphically displaying a problem can drive a point home to decisionmakers, the public, and any other interested stakeholders, he says.

For instance, GIS data can pinpoint and show a problem area, say, an intersection with a high rate of injury crashes. It may further show problems with nearby intersections and graphically reveal a swath of areas, perhaps a whole transportation corridor, that warrants attention by safety professionals. "A picture really is worth a thousand words," Reider says.

Screen shot of the Transportation Explorer Information Portal (TREX).
Screen shot of the Transportation Explorer Information Portal (TREX).

The GIS system serves as a conduit of sorts, he says. Just as NDOT headquarters staff can go to local authorities to point out a problem revealed by GIS, field personnel can transmit information back to educate headquarters about a safety issue.

Virginia

The Virginia Department of Transportation (VDOT) used GIS to facilitate an improved working relationship with its partner agencies. VDOT formed a partnership with the Virginia Natural Heritage Program (VNHP) to develop a spatial database of natural heritage resources. VNHP—with the mission to identify, protect, and preserve Virginia's biodiversity—did not have the financial resources to develop a GIS database to catalog and monitor those resources. Because the two agencies shared a need for the data, VDOT entered into an agreement with VNHP to fund the development of the database. Once the agencies agreed that the basic structure of the first iteration would consist of comprehensive conservation sites coverage and thorough metadata, VDOT provided $119,000 for staff and $4,000 for computers. A memorandum of agreement outlined the terms of use of the resulting natural resource heritage data and ensured that VDOT would have no-fee access to the database for 5 years.

As expected, the agreement has proven mutually beneficial. The database has provided VDOT with easy access to data that were previously difficult to locate, enabled regional visualization of resource distribution, simplified decisionmaking, and created the ability to streamline project review procedures. For VNHP, advantages include a reduction in the volume of projects to review for VDOT, enhanced ability to respond to problem projects, and the database itself, which enables the agency to fulfill its mission more effectively.

GIS maps, such as the one shown here for an area in Virginia, can display environmentally sensitive sites that need to be avoided when constructing new roads.
GIS maps, such as the one shown here for an area in Virginia, can display environmentally sensitive sites that need to be avoided when constructing new roads. Source: VDOT

More generally, GIS has helped VDOT fulfill a mandate for greater openness to the public, says Dan Widner, the agency's GIS program manager. "We are spatially enabling our business processes," he says, to allow for improved tracking of construction and maintenance projects. GIS supports other informational efforts of the agency and helps with integrating information. Clearer data can be supplied to decisionmakers, VDOT constituents, taxpayers, and the public at large, Widner says. "We are making GIS part of our everyday business processes."

Washington

When conducting environmental assessments, the Washington State Department of Transportation (WSDOT) obtains environmental information from its partner resource agencies. Gathering data from many agencies for each project can be a time-consuming process. The Environmental GIS Workbench is a custom-built, online GIS application designed to give WSDOT staff access to a broad range of statewide environmental and natural resource management data. The application is a step toward eliminating redundant data and improving data quality. WSDOT supports the GIS tool by coordinating with numerous Federal, State, and local agencies to ensure that datasets are updated continuously and remain accurate.

With this tool, users are able to produce their own maps that combine environmental data on wetlands, historic sites, and parkland with a proposed highway corridor to see how these natural and cultural resources might be affected. The digitized data layers are available as ArcView® readable files and may be easily downloaded, overlaid, and manipulated.

"The Environmental GIS Workbench was so successful for environmental assessment work that other groups started asking for their own workbench," says Elizabeth Lanzer, environmental GIS/information technology program manager for WSDOT. "Rather than building many different tools, we built an updated workbench that provides GIS support to multiple agency functions."

Screen shot of 'Environmental GIS Workbench' application showing various roadways lacing Washington State.
Screen shot of "Environmental GIS Workbench" application showing various roadways lacing Washington State.

The project has seen promising results. The increased availability of information has reduced decision review time, while centralized control of the system by WSDOT continues to maintain and improve data accuracy.

How to Learn More

With more and more States interested in geospatial technologies, FHWA has worked to provide opportunities for States to come together and share their knowledge and experiences. The National Highway Institute offers a course, Applying GIS and Spatial Data Technologies in Transportation (FHWA-NHI-151039), that helps managers at State DOTs become familiar with geospatial technologies and their relevance to transportation planning. Also, the GIS for Environmental Streamlining and Stewardship workshop, developed by the FHWA Resource Center, provides opportunities for State DOTs and resource agencies to learn about and discuss other States' experiences with GIS related to environmental streamlining. See www.nhi.fhwa.dot.gov/ or www.fhwa.dot.gov/resourcecenter/ for more information about these training opportunities.

In the summer of 2006, the FHWA Office of Project Development and Environmental Review will offer workshops on Application of Conservation Planning Tools for Transportation Planning and Project Development. The workshops, cosponsored with NatureServe and Defenders of Wildlife, will focus on coordinating State conservation and transportation planning and the GIS tools available to help.

Finally, FHWA has a "GIS in Transportation"Web site (http://gis.fhwa.dot.gov), which highlights innovative transportation-related applications of GIS across the country.

This user-created map showing lynx habitat in Washington State was made with the Environmental GIS Workbench to better plan the development of transportation corridor.
This user-created map showing lynx habitat in Washington State was made with the Environmental GIS Workbench to better plan the development of transportation corridor.

In addition to these resources, a GIS-T (GIS for Transportation) Symposium in Columbus, OH, was held March 27-29, 2006. Hosted by the American Association of State Highway and Transportation Officials, Urban and Regional Information Systems Association, Highway Engineering Exchange Program, and the U.S. Department of Transportation, the workshop offered an opportunity for State DOTs interested in using geospatial technologies to learn from the experiences of others.

From high-tech mapping to information sharing, many State DOTs have seen the benefits of using geospatial technologies. GIS allows for complex analyses, easily understandable graphics, and scenario comparison. Indirectly, it has facilitated improved working relationships between State DOTs and their partner resource agencies.

Mark Sarmiento is a planning analyst with FHWA's Office of Interstate and Border Planning. Currently he is promoting the use of geospatial technologies by State DOTs and metropolitan planning organizations. He has been with FHWA since 1995. He has a bachelor's degree in civil engineering from Worcester Polytechnic Institute and a master's degree in civil engineering, with a concentration in transportation, from the University of Virginia.

Lindsay Banks is a GIS specialist with FHWA. Her position in the Office of Interstate and Border Planning focuses on promoting advanced geospatial technology at the State DOT level. She has a bachelor's degree in urban planning from the University of Illinois at Urbana-Champaign and a master's degree in GIS from the University of Redlands.

For more information, contact Lindsay Banks at lindsay.banks@fhwa.dot.gov or Mark Sarmiento at mark.sarmiento@fhwa.dot.gov.

GIS is an FHWA priority, market-ready technology and innovation. For more information, see www.fhwa.dot.gov/resourcecenter/teams/planning/plan_5gis.pdf.

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