Improvements in Highway Maintenance Management in Greece Dimitrios D. Theodorakopoulos, Athanasios P. Chassiakos, and Ioannis D. Manariotis The main features of a computerized system to provide deci­ result of particular oddities that are encountered in each sion support to the agencies involved in highway maintenance agency, the transfer and implementation of an existing management in Greece are presented. Development of the PMS may not be feasible and always must consider the system focuses initially on pavement management, with other local conditions. In addition, lack of historical data and highway elements (e.g., side slopes, bridges) to be considered models to predict pavement performance under local at a later stage. The system includes a database and modules conditions leads to requirements of increased time and for pavement performance prediction, resource allocation, effort to set up a new PMS. and project management. In addition, a user interface system In a recent survey in 60 agencies in the United States with appropriately designed input/output forms and GIS data and Canada, the most common parameters for pavement representation improves applicability. The major pavement condition assessment (and data collected in the corre­ defects are cracking (mostly alligator type, longitudinal, and sponding PMSs) are surface distresses, roughness, friction, transverse), potholes, corrugations and rutting, bleeding, rav­ and structural capacity (2). Pavement condition perfor­ eling, and polished aggregate, which results in high roughness mance is being expressed with combinations of indices and low skid resistance. These defects are represented in the derived from the above data types. To name a few, the system by four parameters: cracking index, index to the first PMS of Arizona initially had included four parameters: cracking, roughness index, and skid resistance index. Further, cracking, index to the first cracking, change in the amount a number of possible treatments have been identified and de­ of cracking during the previous year, and roughness. scribed in terms of materials, methods, machinery, and cost Because of the large number of condition states produced requirements. For each defect, all feasible treatments are con­ by this classification, "cracking during the previous year" sidered, and the best maintenance strategy is produced con­ was omitted later to make the analysis more flexible (3). sidering relative costs, funding availability, and maintenance Skid resistance data were collected but not regarded as a needs over time within the network. major input into the PMS whereas deflection data were collected for pavement design (4). In North Dakota, three indicators were developed for pavement performance assessment: an overall distress index, a structural index, avement management y t ms {PMSs) have been and a roughness index (5). In South Dakota, pavement per­ used ince 1970 to provide decision support in the formance curves were developed using individual indices Pmanagement process, but many agencies in variou (fatigue cracking index, transverse cracking index, rut countries still do not use them in their management activ­ depth index, and ride index), and a composite index was ities (1). A difficulty in implementing a PMS is that, as a used to describe the overall pavement (6). Pavement management systems developed in Europe Department of Civil Engineering, University of Patras, Greece, 26500. include various combinations of indices. In Finland, 249 250 PROCEEDINGS OF THE NINTH MAINTENANCE MANAGEMENT CONFERENCE the system considers bearing capacity, pavement defects • Cracking initiation and progression in new asphalt (alligator cracking, longitudinal cracking, and patching), concrete pavements, asphalt overlays, or slurry seal; rutting, and roughness (7, 8). In Germany, data are col­ • Raveling initiation in slurry seal surfaces; and lected for longitudinal and transverse unevenness, skid • Skid resistance in new pavements. resistance, and surface damage (cracking, raveling, and patching) (9). In Denmark, the system considers longi­ The overall pavement condition is described by a com­ tudinal unevenness, skid resistance, and rutting (10). In posite index of 17 distresses. Each distress is classified Hungary, pavement condition is evaluated in terms of according to its importance, severity, and extent of ap­ structural capacity, unevenness, pavement surface qual­ pearance. Simplified rules for maintenance decisions are ity, rut depth, and drainage condition (11 ). In Spain two based on preset thresholds related to the extent of ap­ indices are used: a structural index (resulting from fatigue pearance of the main distresses. If a specific threshold distresses) and a friction index (12). - - is exceeded, a decision for appropriate action is made. An important element with direct consequences on PMS Otherwise, only routine maintenance is applied. effectiveness is the procedure used for predicting future A new maintenance management system is being dev­ pavPmPnt conrtition. PrPrtirtion i<: gPnPr<>lly pPrfnrmPr1 yi., eloped for application in the highway network of Greece. the followine; methods: It is expected to provide decision support to maintenance agencies for planning, budgeting, scheduling, and perform­ • With relationships transferred from other appli- ing maintenance actions in order to keep the road network cations, at or above the desired level of performance. Manage­ • With relationships derived from existing data, ment will include all maintenance aspects (pavements, side • With probabilistic methods based on existing data, or slopes, bridges, etc.). At this stage, however, the focus is on • By using expert opinion. pavement management. With respect to side slopes, the stahility of rnts and embankments will be considered, pre­ Deterministic relationships have been developed and re­ diction of possible failure will be attempted, and preven­ ported in the literature based on long-term data collection tive maintenance actions will be sought. The main steps of in various countries (13). Direct transferring among ap­ the work are plications allows immediate implementation; however, results may not be effectively transferred from one region • Analysis of user requirements and investigation of to another. In addition, there is limited flexibility to in­ pavement defects and maintenance practice, clude desirable parameters that are different from or • Model development for assessing pavement behavior additional to the ones provided in the model. The second through time, method requires the existence of data within an appro- '"' .. ; ...... '° f-;m ca ("'_,......, +-" 9" 0 ,...l; n+-;,...,..ll.~ rl,...~,...-;1-,. ,... .-- .. ~,...__.. .., _._ - ~·· • Development of a methodology for resource allo­ y .1. .1.u.1..""' Luu~ .:,pau Lv i.va.u.JL-J.\..a..uy u1..,-,t,,..1-J.u\.. 1:-'avc;:111cut pc:1- cation and management, and formance in time. Probabilistic methods are typically • Computer implementation and field application. based on Markov analysis with historical data (7, 14-17). Pavement condition prediction based on expert opinion The system includes a database in which all input and has been used in applications when no historical data are output information is stored and a user interface module available (6, 18). with geographic information system (GIS) representation Maintenance actions can be categorized as follows (13): capabilities. Data collection and analysis issues are also • Routine maintenance (iocal repair of pavement and <liscussed in this paper. shoulder defects, drainage, side slopes, traffic control In recent years, large-scale reconstruction, upgrading, devices, snow and ice control, cleansing, and safety); or new construction of high-speed roads is under way in • Resurfacing (full-width resurfacing of the pavement Greece. The need to keep the road network in an accept­ to preserve surface characteristics and structural integrity); able performance level makes the application of comput­ and erized maintenance management more imperative than • Rehabilitation (full-width and -length surfacing with before. In addition, new highways can provide an ideal selective strengthening and shape correction to restore field laboratory for testing, evaluating the effectiveness, structural integrity or ride quality). and enhancing each element of the system. Maintenance management in Greece has been applied empirically in the past without computerized decision sup­ STRUCTURE OF THE PROPOSED 11. ~. - - • --- --- -- r,. _ _ _ _ port systems. As a resuit, maintenance decis10ns have a lV.ll\l'ljf\ljf<,Mf<.N l ~Y~lf<.M short (1-year) planning horizon. The only noticeable effort toward the development of a PMS is reported by Niko­ The proposed architecture of the system is illustrated in laidis and Evagelidis (19). In this program, pavement per­ a simplified form in Figure 1. The heart of the system is formance prediction is based on World Bank prediction the database where all necessary information (input and models (13) and includes the following parameters: output) is stored. Three modules are used to produce the THEODORAKOPOULOS, CHASSIAKOS, AND MANARIOTIS 251 Pa\"Cm~t pc1(omtMCCI • Geometry data-highway section and length, design f"<dlctioo characteristics (width, number of lanes, shoulder type and width, grade, and curvature); • Pavement design data-pavement type, materials and thickness of layers, material properties [e.g., sub­ grade California bearing ratio (CBR), asphalt content, Resources --+I