Integrating GIS Technology with Transportation Applications

By Stephen Osiecki

22nd Annual Esri International User Conference,

July 11, 2002



Abstract
Transportation studies typically include a wide variety of data. The data needs to be stored in multiple formats, assessed and edited by many team members. For a project to be successful this data must be managed and stored intelligently. This paper presents the integrated use of GIS, CAD and Microsoft Access to manage, analyze and map data for a transportation access management study.

Introduction
Virginia Department of Transportation (VDOT) hired the consulting firm of Vanasse Hangen Brustlin, Inc (VHB) to develop a long-term access management plan for U.S. Route 13 and for a portion of Route 175. The total study area was approximately 70 miles long. In addition to addressing existing safety and operational problems, the plan also took into consideration expected traffic increases through the year 2020.

Due to the overwhelming amount of data that needed to be organized, a GIS needed to be established to manage the data. Microsoft Access was used to store all tabular related data. All roadway design files were prepared in CAD (MicroStation). All impact analysis, cost analysis and thematic mapping was to be performed using a suite of Esri software.

Solution
A route-system of the study roads was created. The route-system allowed for dynamic segmentation of the events in the access databases. This allowed for conventional GIS analysis and thematic mapping of all the resources along the corridor. Resources such as median width, shoulder width, accident locations, driveway location and others were used to help determine what necessary roadway improvements were needed. Also, since the data was stored in Microsoft Access it allowed for non-GIS users to view and modify the data.

Highway engineers created all their roadway design files in MicroStation. There were five different alternatives for the corridor. Each alternative needed to be analyzed and thematically mapped. Using ArcMAP all the CAD files were overlaid over the GIS base, along with all the GIS resource layers and thematically mapped. Since the highway design files were kept in there native environment (CAD) this allowed the highway engineers to modify there alternative throughout the project without having to perform any file conversions.

Another challenge was printing all five alternatives out for internal review and reports. There were a total of eighty 11x17 sheets for each alternative, with a grand total of 400 sheets. An automated printing extension (APE) was written and used to produce the maps. The APE allowed the user to select a layout, scale and how many sheets to print. This extension then automatically process each sheet and create pdf files. Not only did APE streamline the printing process, it also eliminated the chance for user error.

The final challenge was the impact and cost analysis. Since all the highway design files were in CAD and all the resource data was in GIS, a data conversion was performed. After all the highway design files were finalized they were converted to geodatabases for analysis. First the impact analysis was performed. Water resources, wetlands, historic and archeological areas among other resources were analyzed. Second was the cost analysis. Since the geodatabases contained all the levels (layers) from CAD files we were able to associate a cost for each recommended improvement. For example, a unit cost for removal of pavement, closed medians, proposed medians, new pavement, etc. was used in the analysis. This allowed for comprehensive cost analysis for each alternative. The results where put into a Microsoft Access database for dissemination to the project team.

Conclusion
Using GIS we where able to store, manage, analyze and map thousands of records of information. Since we where able to map and analyze the highway engineers CAD files duplicate efforts between disciplines where minimized and production was more efficient. This allowed for cost savings and collaboration for all team members on the project.

Stephen Osiecki.

GIS Specialist

VHB Inc.

101 Walnut Street

Watertown, MA 02471

(617) 924-1770

sosiecki@vhb.com