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GIS: GIS Moves California's Motorists Toward the 21st Century
Faced with the job of caring for 18,000 miles of highway and 34,000 bridges, the California Department of Transportation designs a next-generation GIS.
By Jim Springer One in every nine Americans - more than 32 million people - lives in California. Tourists from throughout the U.S. and the world visit our world-class cities, beaches, and state and national parks. If it were an independent country, California would rank as the worlds eighth-leading industrial power. And people and goods travel, for the most part, by highway. Drivers recorded more than 144 billion vehicle miles in California during the 12-month period that ended June 30, 1996. The California Department of Transportation - Caltrans - cares for 18,000 miles of state highways, as well as interstate freeways and county roads. The departments 1996 highway budget approaches $6 billion.
To provide the best available data to plan, design, construct, maintain and manage Californias highways, Caltrans has adopted a new geographic information system (GIS) based on high-performance workstations from Hewlett-Packard Company, software from Environmental Systems Research Institute (ESRI), and relational database technology from Oracle Corp. GIS: An Essential Capability
The ability to study, track and manipulate geographic data is essential to every phase of the the departments highway projects. A small improvement in that ability can produce a large improvement in the delivery of those projects.
Most of the departments data is tied to one of two geographic systems - the County-Route-Postmile System and the California Coordinate System. The Postmile system is a linear measurement system based upon the distance along the centerline of the highway. Caltrans engineers and planners have a common framework to easily access and analyze information from databases based upon this County-Route-Postmile index. Information such as traffic volume, posted speeds, accident records, maintenance history, etc. can be related geographically to the highway maps based upon this scheme.
Managers also need to save money and time in planning and completing projects. A GIS gives them access to up-to-date and easily understood information to ease the public hearing process, and allows them to make better and more timely decisions. The GIS also is able to incorporate information from other sources, such as maps from the U.S. Geological Survey, and useful data from other government agencies. In Planning: Avoiding Endangered Species
The GIS is being designed to help Caltrans save time and money by accurately determining right-of-way costs (by accessing tax assessors data), properly planning route locations, and developing accurate maps and presentations for approval hearings and community meetings.
A state of great natural beauty, California must balance strong environmental concerns with the need for a better transportation infrastructure. In the Marysville district office, the GIS is helping the agency save time in planning routes in environmentally sensitive areas. Habitat information - about endangered animal and plant species, soil problems, and other factors - has been entered into the system, letting highway planners avoid months of potential delay by locating routes away from these areas. In Preparation: Studying Seismic Conditions
California is prey to natural emergencies, among them floods, slides and earthquakes. After such an event, repairing and maintaining the states roads and bridges - such as the San Francisco Bay Bridge, damaged by the October 1989 quake, and the heavily traveled Santa Monica Freeway, damaged in January 1994 - are huge undertakings. But GIS technology is being used in planning for the next major earthquake. For example, the GIS is being used to map earthquake faults to the states highway system. Caltrans engineers are mapping the locations of newly discovered faults and analyzing how they might affect highways and bridges in the area. The GIS collects the critical information needed - including the fault type and location, the bridge and soil type, the intensity of peak ground acceleration, and peak acceleration contours based on the maximum credible earthquake - to help the department make better decisions about retrofitting existing bridges and building new ones. A Green Light to GIS
The current GIS is part of a comprehensive project that began in early 1989, when an extensive pilot study was undertaken to determine if a geographic information system would meet the departments requirements. Headquarters personnel using data from district offices weighed the costs and benefits of GIS technology. These pilots, plus studies by other state departments of transportation, showed that a GIS would be used very effectively at Caltrans.
A full range of software and hardware solutions was evaluated before the GIS solution began implementation in 1993. In its initial phase, the GIS consists of more than one hundred HP 9000 Model 715 workstations, including 50-Mhz and 80-MHz models with 32M bytes of RAM and 1G byte hard disks. Selecting Hardware and Software
For GIS software, Caltrans chose ARC/INFO and ARC/VIEW from ESRI. Oracle was chosen as the relational database management system. District offices are being networked via a 10BaseT Ethernet LAN, and a wide-area network links the 12 offices together.
HP was chosen as the hardware platform for the CAD and GIS software. Caltrans wanted to make sure that its roadway design legacy applications and MicroStation CAD software used on the previous hardware system (which consisted of both Intergraph and Apollo workstations) would be able to run on the new hardware. Benefits Across the Project Cycle
The departments GIS will automate key business functions. In addition to planning, these include:
Project Design. In the detailed design phase, the GIS will permit engineers to access information about traffic estimates, utilities, hydrology, and other attributes. This will enable engineers to prepare for environmental reviews, design all elements of the project, and estimate its cost.
Maintenance. The GIS will help the maintenance division map areas where repairs are needed, join separate locations into a unified project for efficient management, and estimate costs. It will also allow the department to precisely assess highway maintenance needs in its annual budget presentations (which is called the State of the Pavement Address ) to the state legislature.
Alternative Transportation Planning. The GIS will contain information on all types of transportation - airplanes, rail and light rail, buses, car pools, etc. - to enable planners to display and map how the different modes may be combined for maximum transit efficiency and minimal environmental impact.
Information Dissemination. Because the GIS can incorporate data from a variety of sources and display it in an easily understood manner, it will be used to keep other government bodies and regulatory agencies - and the general public - fully and clearly informed about projects the department is planning or undertaking.
Compliance. The GIS will help in the pursuit of federal highway funds, demonstrating Californias compliance with federal requirements for safety, bridge rehabilitation, air quality, traffic congestion, pavement conditions, and other issues. It also will assist the department in cooperating with the California legislature and state agencies charged with making highway laws and regulations. Keeping the Lifeline Open
Californias roadways are the lifelines of the states commerce and industry. Caltrans anticipates the implementation of a state-wide GIS will ultimately save money and improve motorists safety, mileage and travel time by effectively maintaining existing roads and bridges and delivering new projects on time. About the Author:
Jim Springer is a senior transportation engineer and chief of GIS development for Caltrans. He may be reached at 916-227-2627.
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