Road Extraction Using Spectral Mixture

USE OF REMOTELY SENSED PAVEMENT DATA FOR NEEDSASSESSMENT, PRIORITIZATION AND RESOURCE ALLOCATION, ANDMAINTENANCE PERFORMANCE EVALUATIONZachary HansResearch [email protected] Omar SmadiPavement Management [email protected] for Transportation Research and Education, Iowa State University2901 S. Loop Drive, Suite 3100, Ames, Iowa 50010-8632Phone (515) 294-8103, Fax (515) 294-0467Theme: remote sensing, pavement managementAbstractDecreases in funding and restrictions on new construction have made itincreasingly more important to effectively and efficiently manage existinginfrastructure. For highway operating agencies, maintenance and rehabilitationof the roadways often requires the greatest portion of their annual operatingbudget. Therefore, many agencies have initiated a pavement managementsystem to assist in making better decisions about their roadways. Pavementmanagement systems, however, are data intensive programs, requiringinformation regarding pavement condition, history, and performance as well asmaintenance and rehabilitation strategies and costs. Traditionally, pavementcondition data have been obtained through manual surveys. These surveys areoften costly, time consuming, and potentially dangerous to field personal.Depending on the size of the agency and extent of the roadways system, only arepresentative “sample” of pavement condition may be collected. Even withtrained, experienced field personnel, these sample data may still be largelysubjective, resulting in inconsistencies in system-wide comparisons and multi-year analyses.Van-based, remote sensing technology provides a relatively inexpensive,objective, repeatable means to collect and interpret the pavement condition datanecessary for pavement management systems. This paper will discuss threeapplications of van-based, remotely sensed pavement condition data within theState of Iowa. These applications include needs assessment, prioritization andresource allocation, and maintenance performance evaluation. The authors willfirst discuss use of biennial, remotely sensed pavement data for distribution ofstatewide road use tax funds. Given that pavement condition is a majorcomponent in the existing allocation program, the authors will address how useof biennial, remotely sensed pavement data can reduce the variability in needs assessment and subsequent funding allocation resulting from data timelinessand quality. Second, the authors will discuss how state and local highwayoperating agencies are utilizing remotely sensed pavement data in theirpavement management efforts. Emphasis is placed on development and use ofsummarized pavement condition data within a multi-year, prioritization programas well as use of GIS for data visualization and aggregation. Lastly, the authorswill discuss efforts to utilize remotely sensed pavement data to better quantify theimprovements associated with individual maintenance strategies anddemonstrate the benefit of utilizing these relationships in pavement management,specifically the tradeoffs between pavement rehabilitation and maintenance. Identification Of Access Elements For Safety Analysis Using AerialPhotographySubmitted and Accepted at GIS-T, Arlington, VA. April 2001.The paper attempts to develop a methodology to rank the safety of roadsegments based on their access management using aerial photography. Aerialphotography would be used to extract access related data elements that wouldform the basis for the proposed ranking methodology. Digitized crash statistics ofthe road segments under consideration will be used to relate the rankingmethodology to safety. The developed ranking using aerials would be comparedwith the ranking developed using the “ground truth”. The paper will address thepossibility of replacing the time-consuming on road data collection method byaerial photography. Use of Remote Sensing to Evaluate Pavement Marking ConditionsSubmitted and Accepted at GIS-T, Arlington, VA. April 2001.Remote sensing has become widely used for a variety of applications inmany fields. Although it has not been fully exploited in the transportation arena,it does provide the opportunity to improve on existing procedures and exploit newtechnologies. This paper discusses the use of remotely sensed data foridentification of pavement marking condition. Current procedures for evaluationof pavement marking condition are labor intensive and time consuming. Usingortho-photos, pavement marking condition can be evaluated and inventoried.This paper evaluates and recommends the image resolution and spatial accuracynecessary to identify specific pavement marking condition, describes themethodology, and makes recommendations on the use of remote sensing forevaluation of pavement marking condition for DOT’s. Also discussed are thecosts and benefits of using remote sensing compared to traditional methodsincluding reduced potential for accidents in the field, better equipment utilizationand reduced disruption to traffic. The end result of the research is creation of anew or population of an existing linear referencing method in GIS with pavementmarking condition attributes. Roadway Feature Collection David VenezianoStudent Paper Submitted to Consortium for Geographic Information Science (UCGIS) AnnualAssembly and Summer Retreat from June 21-24 at the University at Buffalo inBuffalo, New York The collection and recording of general roadway characteristics andinfrastructure element data such as lane widths is a labor and time intensiveprocess. Current collection techniques, such as manual and van-based methodsare often tedious and inefficient. While technological advances have producedsome promising alternative collection methods, none hold the same potential asa GIS. Ongoing research is focused on the development and application ofcollection methods utilizing a GIS and remotely sensed imagery. Suchtechniques would allow easy extraction of a wealth of data which was previouslydifficult and costly to obtain.The primary objective of the research is to develop a technique utilizing a GISand remotely sensed imagery to collect, measure and record intersectioncharacteristics and infrastructure element data. The ability to quickly performsuch tasks in one software package is what makes the utilization of a GISespecially attractive for this application. Additional objectives of the researchinclude determining the resolution(s) of imagery required for data extraction andthe respective costs for this new technique, which will allow comparison of theGIS collection method to existing methods. The poster will present the results ofthis research work.The technique currently under development can be classified as being point andclick, with the majority of identification and recording work being performed bymanual interpretation. The technique employs several steps to determine,extract and record roadway attributes and characteristics. The foremost potentialimpact of this technique is that it creates far more detailed databases than arecurrently possible due to the constraints of limited data collection. Thesedatabases can be updated more frequently, as remotely sensed data such assatellite imagery provides relatively recent images to work with. Additionally, ascollection is being performed in a GIS, workers are not required to go into thefield to gather data, eliminating the potential for accidents to occur. EXTRACTION OF ACCESS ELEMENTS USING AERIAL PHOTOGRAPHY Srinivasa Rao Veeramallu Student PaperSubmitted to Consortium for Geographic Information Science (UCGIS) AnnualAssembly and Summer Retreat from June 21-24 at the University at Buffalo inBuffalo, New York The decision-making process involved in maintaining and improving vast,valuable and diversified transportation assets is becoming a complex issue.Performance measurement of the road network is a very important aspect of thedecision-making process that depends on transportation infrastructuredatabases. Efficient and accurate extraction of the data elements from theexisting road network is often time consuming and resource intensive.Geographical Information Systems (GIS) with aerial photography provide asolution to effectively mitigate this problem.Access Management is an area where data needs are becoming an issue.Recent surveys conducted by the researchers indicate most of the surveyedstate DOTs do not have comprehensive access related data. The survey alsoindicated an inclination for maintaining comprehensive access related data. Thisposter specifically deals with extraction of access related data elements usingaerial photography. ArcView, a desktop GIS package, was used to analyzedigital aerial images for creation of a comprehensive database for access relateddata elements.