DEVELOPMENT OF PROTOTYPE HIGHWAY ASSET MANAGEMENT SYSTEM

Transcription

1 DEVELOPMENT OF PROTOTYPE HIGHWAY ASSET MANAGEMENT SYSTEM By Nasir G. Gharaibeh, 1 Michael I. Darter, 2 Member, ASCE, ad Doald R. Uzarski, 3 Member, ASCE Dowloaded from ascelibrary.org by Uiversity of Illiois At Urbaa o 02/13/15. Copyright ASCE. For persoal use oly; all rights reserved. INTRODUCTION ABSTRACT: A prototype methodology for itegratig highway ifrastructure maagemet activities has bee developed. This paper describes the aalytical procedures ad data itegratio ad presetatio methods as well as the geographic iformatio system- (GIS-) based software system that ties together ad implemets the data ad maagemet procedures. Together these elemets comprise the ew methodology. There are four major areas of itegratio cosidered i the methodology: (1) Itegrated computerized system; (2) etwork-level itegratio; (3) project-level itegratio; ad (4) multiple performace measures. The etwork-level itegratio ivolves performig trade-off aalysis to select cadidate projects from various highway ifrastructure compoets. The project-level itegratio icludes idetifyig adjacet improvemet projects from various ifrastructure compoets that ca be implemeted simultaeously to reduce traffic disruptios. The project-level itegratio is performed i a spatial maer usig GIS capabilities. The itegrated system approach developed i this study for the maagemet of highway assets was applied to five ifrastructure compoets (pavemets, bridges, culverts, itersectios, ad sigs) of the state highway system i Champaig Couty i cetral Illiois. The sample highway applicatio showed that coordiatig project implemetatio is beeficial for highway agecies ad users. It reduces disruptio to ormal traffic flow caused by rehabilitatio ad recostructio activities i a 5-year program by 20%. Highway agecies are cotiually ivestig large sums of moey to maitai the physical ad operatioal quality of their ifrastructure assets above miimum levels. A highway ifrastructure etwork cosists of may compoets that are ormally owed ad maaged by the same agecy (e.g., pavemets, bridges, culverts, sigs, itersectios, ad guardrails). Thus, it is logical to expect that maagig these compoets i a coordiated maer is beeficial to both users ad owers. Highway ifrastructure maagemet is essetially a set of activities associated with the process of maitaiig, rehabilitatig, ad recostructig/replacig highway assets i a cost-effective way. Thus, highway agecies eed tools that allow them to perform coordiated maagemet of their assets ad that provide the services that the commuity expects of them withi fudig limits. I may highway agecies, separate maagemet systems are ofte icompatible i terms of locatio referecig systems, aalytical procedures, ad data iput/output format. Thus, data sharig ad commuicatio amog these systems become impractical ad expesive. The mai objective of this research is to provide highway agecies at the state, couty, or muicipality with a methodology for developig tools that ca be used to evaluate the trade-offs amog various highway improvemet projects ad coordiate project implemetatio to reduce traffic disruptios. I other words, this prototype methodology ca be used for maagig various highway ifrastructure compoets i a coordiated ad cost-effective maer. The methodology cosists of aalytical procedures ad data itegratio ad presetatio tools, alog with the geographic iformatio system- 1 Res. Egr., ERES Cosultats, Ic., 505 W. Uiversity, Champaig, IL [email protected] 2 Pres., ERES Cosultats, Ic., 505 W. Uiversity, Champaig, IL. 3 Pri. Ivestigator, U.S. Army Costr. Egrg. Res. Lab., Champaig, IL Note. Associate Editor: Keeth Maser. Discussio ope util November 1, To exted the closig date oe moth, a writte request must be filed with the ASCE Maager of Jourals. The mauscript for this paper was submitted for review ad possible publicatio o May 4, This paper is part of the Joural of Ifrastructure Systems, Vol. 5, No. 2, Jue, ASCE, ISSN /99/ /$8.00 $.50 per page. Paper No (GIS-) based software (called IfraMaage) that itegrates ad implemets those procedures ad tools. METHODOLOGY DESCRIPTION Sigificat efforts have bee made to develop maagemet systems to improve efficiecy i utilizig limited trasportatio resources (e.g., pavemet maagemet systems ad bridge maagemet systems). However, there has bee much less work doe to develop a total highway ifrastructure maagemet methodology that ties these systems together. Durig the late 1980s, discussios bega o the importace of a comprehesive system for maagig highway ifrastructure compoets such as pavemets, bridges, culverts, ad traffic cotrol devices i a coordiated maer to improve maagerial decisios. However, very few specifics have bee stated i this regard. Oe of the early efforts i the area of urba ifrastructure maagemet was made by the Urba Istitute ad the Iteratioal City Maagemet Associatio i the early 1970s to idetify measures of effectiveess for basic muicipal services (e.g., trasportatio, solid waste collectio, water supply, sewage) (Measurig 1974). However, the real-world use of these effectiveess measures is still largely utested (Grigg 1988). The eed for a total highway maagemet system ad geeral guidelies for developig it were discussed by Siha ad Fwa (1989). Stephese (1987) described the approach take by the city of Orlado, Fla., to develop itegrated street ifrastructure iformatio systems that operate from a commo street ivetory. Similar systems are used by some muicipalities to provide performace ad ivetory iformatio related to urba ifrastructures, such as pavemets, sewers, gas, ad electric (Perso ad O Day 1986; Zhag et al. 1994; Lee ad Deighto 1995). However, most of these systems do ot have the ecessary decisio support aalytical techiques, such as life cycle cost aalysis, utility theory, ad optimizatio techiques. These techiques are eeded to perform reasoable itegratio of egieerig as well as ecoomic decisios. Oe of the few efforts that established specifics for itegratig highway ifrastructure maagemet systems is that of Harper ad Majidzadeh (1993) to develop a itegrated pavemet ad bridge maagemet system for the kigdom of Saudi Arabia usig fuzzy set theory to defie optimal alteratives. The Fiish Natioal Road Admiistratio coupled bridge ad JOURNAL OF INFRASTRUCTURE SYSTEMS / JUNE 1999 / 61

2 pavemet maagemet systems ito oe ifrastructure maagemet system to optimize simultaeously bridge ad pavemet maiteace ad rehabilitatio activities uder a sigle set of costraits ad budget (Mäistö ad Tapio 1994). Other valuable efforts to itegrate bridge ad pavemet maagemet systems were made by Ravirala ad Grivas (1995) usig goal programmig. This paper describes a prototype methodology for maagig multiple highway ifrastructure assets i a coordiated ad cost-effective maer. Key features of this methodology are summarized as follows: GIS-based software system Ivestmet trade-offs (etwork-level itegratio) Coordiatio of project implemetatio (project-level itegratio) This methodology also cosiders multiple performace measures i the selectio of cadidate ifrastructure improvemet projects. Spatial ad statistical aalysis of pavemet coditio, safety, ad traffic data coducted o the state highway system i Champaig Couty, Ill., revealed that the itegratio of pavemet, safety, ad cogestio maagemet systems is particularly critical i urba areas (Gharaibeh et al. 1997). Software System A essetial tool for applyig the ew highway ifrastructure maagemet methodology efficietly is a computer software system that icludes a set of appropriate egieerig, ecoomic, ad spatial methods, i additio to highway ifrastructure data. This is a GIS-based sigle system architecture that icludes the combiatio of various highway ifrastructure asset maagemet systems. This system icorporates several tools (i.e., data, database maagemet fuctios, aalytical methods, ad iformatio presetatio techiques). The potetial value of each highway maagemet system is exteded beyod its idividual scope by allowig egieers ad egieerig maagers to coordiate decisios at the plaig, maagemet, ad operatioal levels withi the highway agecy. The IfraMaage prototype GIS-based ifrastructure maagemet system is developed to maage five highway compoets (pavemets, bridges, culverts, sigs, ad itersectios) i a coordiated maer. The system desig ad operatio procedure of the IfraMaage software are summarized i Fig. 1. IfraMaage was developed usig versio 7.04 of the ARC/ INFO eviromet, a well-established GIS developed by the Evirometal Systems Research Istitute (Uderstadig 1994). Liear data i IfraMaage is desiged usig the routesystem liear data model. Milepost is the commo locatio referecig system for all data. This model is used to represet liear features (called routes) ad their associated attributes (called evets) so that the dyamic segmetatio mechaism ca be utilized. Major advatages of a itegrated ifrastructure maagemet software are as follows: Itegrated database ad commo liear referecig system Compatible aalytical procedures Compatible output presetatio methods Potetial for reduced software developmet, maiteace, ad operatio costs Potetial for reduced traiig costs FIG. 1. System Desig for Highway Ifrastructure Maagemet 62 / JOURNAL OF INFRASTRUCTURE SYSTEMS / JUNE 1999

3 Network-Level Itegratio This is a trade-off aalysis amog alterative ivestmet strategies that allows for the selectio of improvemet projects from various ifrastructure compoets to maximize the overall performace of the highway etwork ow ad i the future, withi fudig limits. For example, to improve the overall performace of a highway ifrastructure etwork, it may be more appropriate to shift a portio of the pavemet fuds to bridges, or vice versa. As ca be see from Fig. 2, the etwork-level itegratio is performed i two steps: 1. Allocate a total etwork aual budget across competig compoets 2. Allocate the optimum share of each compoet from the total budget across the competig projects withi the compoet To formulate the above procedure i optimizatio problems, it is ecessary to measure the beefit of improvemet for each ifrastructure compoet, to develop a commo ifrastructure performace idicator for all compoets, ad to develop mathematical relatioships betwee ivestmet level (i.e., budget) ad ifrastructure performace. Measurig Beefits of Ifrastructure Improvemet Vehicle miles traveled over adequate ifrastructure (VMT- A) over the improvemet life was idetified as a reasoable measure of improvemet beefits for liear highway features. Number of vehicles usig a adequate ifrastructure (VU-A) was idetified as a reasoable measure of improvemet beefits for poit highway features. VMT-A ad VU-A cosider improvemet life ad traffic; for liear features, project legth is also cosidered. Adequacy is defied based o thresholds of multiple performace measures. For example, a pavemet sectio is cosidered adequate if the pavemet coditio, accidet rate, ad volume-to-capacity ratio (V/C) have ot reached pre-specified thresholds. Idividual Ivestmet-Performace Fuctios The cocept of efficiecy was developed ad used i this study as a ifrastructure performace idicator. For liear features (e.g., pavemet), efficiecy is defied as the ratio of the total VMT-A over the ifrastructure life to the total VMT- A computed with a ulimited budget. For poit features (e.g., itersectios), efficiecy is defied as the ratio of the total VU- A to the total VU-A computed with a ulimited budget. Efficiecy is expressed i percetage uits. Thus, with a highway ifrastructure compoet of 100% efficiecy, all users would be drivig o or usig ifrastructure features i adequate coditio for the logest possible period of time. O the other extreme, with a highway ifrastructure compoet of zero efficiecy, oe of the users would be drivig o or usig ifrastructure features i adequate coditio. Percet adequate (e.g., 80% of the bridges i the ifrastructure etwork are adequate) ca also be used as a performace idicator; however, it is ot discussed i this paper (Gharaibeh 1997). To determie the optimum allocatio of the total budget across the competig compoets, it is ecessary to develop a mathematical model that represets the relatioship betwee ivestmet level ad efficiecy for each ifrastructure compoet i every year of the improvemet program. Usig data for the state highway system i Champaig Couty, Ill., it was foud that the expoetial form is a reasoable ad simple best-fit regressio fuctio for this relatioship. Thus, the fuctioal form of the ivestmet-performace fuctio is b Performace = a (ivestmet) where performace is expressed i terms of efficiecy or percet adequate, ivestmet is expressed i terms of dollars, ad a ad b are regressio coefficiets. It is ecessary to ote that the values of the a ad b factors deped o the ifrastructure coditio i the curret year ad, cosequetly, o the ivestmet levels ad ifrastructure coditio i previous years. As the ivestmet level i previous years icreases ad the ifrastructure coditio improves, the slope of the ivestmet-performace curve i the curret year decreases (i.e., a approaches 100 ad b approaches 0). A example of the ivestmet-efficiecy fuctio for pavemets o the state highway system i Champaig Couty, Ill., is show i Fig. 3. Across Compoets Budget Allocatio This optimizatio problem is formulated as follows: If G = (g 1, g 2, g 3,...,g ) is the vector of aual budget allocatios to ifrastructure compoets, the the across compoets FIG. 2. Network-Level Itegratio Approach Used i Prototype Methodology JOURNAL OF INFRASTRUCTURE SYSTEMS / JUNE 1999 / 63

4 FIG. 3. Pavemet Beefit ad Efficiecy versus Ivestmet Level (Champaig Couty, Year 1996) budget allocatio problem is to determie the optimum value of g for each compoet. The budget portios must add up to the total etwork aual budget or less. The optimizatio problem is to determie the optimal budget allocatio for the highway ifrastructure compoets that maximizes the total performace fuctio (i.e., the objective fuctio) cosiderig budget costraits. Thus, the optimizatio decisio problem is formulated as follows: subject to i=1 max i=1 p i gi G; LBi gi UBi where p i = ifrastructure compoet performace idicator (e.g., efficiecy) expressed as a fuctio of ivestmet level (i.e., budget) of highway ifrastructure compoet i; g i = ivestmet level (or budget) of highway ifrastructure compoet i; G = total highway ifrastructure etwork budget; = umber of highway ifrastructure compoets cosidered i the aalysis; ad LB i ad UB i = lower ad upper bouds of the budget of compoet i. I this study, the idividual budgets lower bouds are set to zero, ad the upper bouds are set at the budget level at which efficiecy reaches 100%, whe the ivestmet-performace curve starts to flatte out. However, the decisio maker ca set the budget bouds (LB i ad UB i ) as desired. The reverse margial aalysis optimizatio algorithm, developed by Basu ad Batra (1984) for advertisig budget allocatio purposes, is used to solve the optimizatio problem. The algorithm cosists of two stages, described as follows. Stage 1 Total budget costrait igored. For each highway compoet i, the budget g i is icreased i small steps of g i to maximize p i util the maximum value of p i is reached. g i is a prespecified small positive quatity betwee LB i ad UB i [ =(UB i LB i )/10,000, where LB i ad UB i are i millio dollars]. Let g max i be the value of g i that maximizes p i. For a cotiuously icreasig fuctio, g max i = UB i. Stage 2 Total budget costrait satisfied. This stage cosists of the followig steps: 1. If i=1 g max i G (where G is the total etwork budget), set g i = g max i for all i ad stop. Otherwise go to Step Fid the highway compoet j that has the miimum margial performace for a additioal budget dollar (i.e., the partial derivative of the ivestmet-performace fuctio with respect to ivestmet) as follows: pj g j i j j g i=g maxi g =g max pi, for i =1,..., g 3. Decrease g j to g j g j (i.e., set g j = g j g j ). 4. If i=1 g i G (where G is the total etwork budget), stop. Otherwise go to Step 2. Basu ad Batra (1984) compared the reverse margial aalysis algorithm with several other optimizatio algorithms ad cocluded that it always gives the best solutios. Withi Compoet Budget Allocatio This problem focuses o the optimum allocatio of each compoet s aual budget (a portio of the total budget) across the competig projects withi the correspodig compoet. I other words, the optimizatio problem is to select FIG. 4. Arragig IBCs of Improvemet Alteratives for Deficiet Feature FIG. 5. Covertig Cocave Up Project-Level Graph to Cocave Dow Oe TABLE 1. Measure (1) Performace Measures Thresholds Threshold (2) (a) Pavemet CRS 6 IRI 2.52 m/km (160 i/mi) V/C 0.95 PAR 10 accidets/mi/year (6.2 accidets/km/year) (b) Bridge DKR 6 SBR 6 SPR 6 VUCLr 4.69 m (14.08 ft) BAR 1 accidet/millio vehicles (c) Itersectio CRS 6 V/C 0.95 IAR 2 accidets/millio vehicles Note: BAR = bridge accidet rate (umber of accidets/millio vehicles eterig bridge); CRS = coditio ratig survey (1-to-9 scale); DKR = bridge deck ratig (0-to-9 scale); IAR = itersectio accidet rate (umber of accidets/millio vehicles eterig itersectio); IRI = iteratioal roughess idex [m/km (i./mi)]; PAR = pavemet accidet rate [umber of accidets/km (mi)]; SBR = bridge substructure ratig (0-to-9 scale); SPR = bridge superstructure ratig (0-to-9 scale); V/C = volume-to-capacity ratio; VUCLr = bridge vertical uder clearace [m (ft)]. 64 / JOURNAL OF INFRASTRUCTURE SYSTEMS / JUNE 1999

5 FIG. 6. Example Spatial Distributio of Cadidate Improvemet Projects (Year 2000) improvemet projects of the ifrastructure compoet uder cosideratio that yield the maximum beefits expected withi the available budget. Icremetal beefit cost (IBC) aalysis is employed to solve this optimizatio problem such that a collectio of aual projects is selected that yields the highest beefits (VMT-A or VU-A) of each ifrastructure compoet expected withi the available aual budget. The IBC method requires the followig iput data to solve the withi compoet budget allocatio problem: Idetificatio of potetial improvemet alteratives for each deficiet feature. Equivalet uiform aual cost (EUAC) of every improvemet alterative for each deficiet feature. Numerical value of beefits expected from every improvemet alterative for each deficiet feature (I this methodology, VMT-A ad VU-A over the improvemet life are used for measurig beefit.) Aual budget. The IBC algorithm process projects cost ad beefit data to select a collectio of projects that maximizes the total beefits i a particular year withi the available budget usig the followig procedure: B i = Bi B i 1 4. The IBC ratio of alterative i is calculated as follows: IBC i = B i/ Ci Ay alterative with a egative IBC ratio is elimiated from ay further aalysis. 5. For each deficiet feature, the costs ad beefits of every improvemet alterative are arraged as show i Fig. 4. The project-level graph should be cocave dow; that is, the IBC ratios must be i descedig order (Shahi et al. 1985; Mohsei et al. 1992). If there is a cocave up portio i the graph, a ew IBC ratio for the alterative with the highest cost withi the cocave up portio (call it alterative j) is computed as follows: New IBC = ( B B )/( C C ) j j j 1 j j 1 The ew IBC ratio esures that the IBC ratios are i decreasig order. The cocave up situatio is explaied 1. For each alterative improvemet, the EUAC ad beefits are calculated. 2. For each deficiet feature, improvemet alteratives are sorted i the icreasig order of their EUAC. 3. The icremetal cost ad beefit of improvemet alterative i are calculated as follows: C i = EUACi EUAC i 1 FIG. 7. Aual Amout of Travel Through Work Zoes with ad without Project-Level Itegratio JOURNAL OF INFRASTRUCTURE SYSTEMS / JUNE 1999 / 65

6 i Fig. 5. The process of covertig a cocave up graph to a cocave dow oe is explaied i the followig steps: a. The begiig ad edig poits of the cocave up portio of a project-level graph are coected by a straight lie. b. The IBC ratio of the alterative with the highest cost withi the cocave up portio (alterative 3 i Fig. 5) is set equal to the slope of the ew lie developed i Step a. The above process is repeated util the whole projectlevel graph becomes cocave dow. For example, i Fig. 5 it is repeated twice. 6. All improvemet alteratives for all deficiet features are arraged i descedig order of the IBC ratio to determie the steepest path. This is sometimes called the etwork IBC curve (Mohsei et al. 1992). I selectig projects for implemetatio, the steepest path is followed util the budget is cosumed. Project-Level Itegratio This aspect of itegratio icludes idetifyig adjacet improvemet projects from various ifrastructure compoets i a particular year that ca be implemeted simultaeously to reduce traffic disruptios. I the absece of coordiatio, coflicts i project implemetatio are likely to occur. For example, pavemet rehabilitatio activities may be performed o a sectio, ad the a few moths later rehabilitatio activities are performed o a culvert located withi the pavemet sectio. Obviously, such ucoordiated projects icrease both agecy costs ad user costs. I IfraMaage, the GIS performs the project-level itegratio i a spatial maer usig the evet overlay fuctio available i ARC/INFO through the dyamic segmetatio process. The adjacecy criteria curretly available i Ifra- Maage are described as follows: All bridge, culvert, ad itersectio projects withi a pavemet sectio that is scheduled for improvemet i a 66 / JOURNAL OF INFRASTRUCTURE SYSTEMS / JUNE 1999 FIG. 8. Spatially Itegrated Improvemet Projects i 1996

7 particular year are idetified as itegrable with the pavemet project. All bridge ad culvert projects withi a user-defied distace [e.g., 83.3 m (250 ft)] from the ceter of a itersectio that is scheduled for improvemet i a particular year are idetified as itegrable with the itersectio project. The effect of project coordiatio o highway users is measured i terms of umber of vehicle-miles drive through work zoes (VMT-WZ). This idicator is a surrogate for several user cost compoets such as delay costs ad vehicle operatig costs that result from drivig through costructio zoes. VMT-WZ is computed for a particular year as follows: VMT-WZ = AADTi* WZLi* DCi i=1 where VMT-WZ = total umber of vehicle-miles drivig through work zoes; AADT i = aual average daily traffic at project i (vehicle/day); WZL i = work zoe legth of project i (mi); DC i = total days of costructio for project i; ad = total umber of ifrastructure improvemet projects. The above equatio was used by Wag (1995) to measure highway uavailability for users. SAMPLE APPLICATION The state highway system i Champaig Couty was used to demostrate the prototype system ad to coduct the ecessary aalysis. Champaig Couty is located i east cetral Illiois i the wet-freeze climate of the Uited States. The state highway system i Champaig Couty cosists of three iterstate routes (I-57, I-72, ad I-74), three atioal routes (US- 45, US-136, ad US-150), ad five state routes (IL-10, IL-47, IL-49, IL-54, ad IL-130). The followig five compoets of the sample ifrastructure etwork are cosidered i the applicatio: 1. Pavemets: 148 pavemet sectios (620 lae-miles of rigid, flexible, ad composite pavemets) 2. Bridges: 128 cocrete ad steel bridges 3. Culverts: 64 cocrete culverts 4. Itersectios: 11 major itersectios (where ay two or more of the cosidered highways itersect) 5. Sigs: 660 sigs (oly sigs o the iterstate highways are cosidered) Table 1 shows the performace measures ad their default thresholds for pavemets, bridges, ad itersectios cosidered i the IfraMaage software ad used i the aalysis. Sigs were visually ispected at ight ad assiged a ratig o a 0-to-9 scale to measure their ight visibility performace. This measure is called sig coditio idex. A sig coditio idex threshold of 6 is used i the aalysis. Also, the performace of culverts is measured usig a ratig o a 0-to-9 scale ad a threshold of 6. This measure is called culvert coditio idex. A 5-year ifrastructure improvemet program ( ) was developed for the sample highway etwork usig performace, moitorig, ivetory, ad cost data for 1995 ad a total aual budget of $6,500,000. The etwork-level itegratio procedures were implemeted to allocate the total budget ad idetify cadidate projects. For example, the map i Fig. 6 shows cadidate ifrastructure improvemet projects for year 2000 that are selected usig optimizatio ad preseted usig GIS. Fig. 7 illustrates the effect of project-level itegratio o the total aual VMT-WZ throughout the sample etwork. The largest aual reductio i VMT-WZ due to project-level itegratio is about 21,000,000 or 40% (31,300,000 versus 52,100,000) ad occurs i the first year of the improvemet program (1996). This is due to the large umber of projects from all ifrastructure compoets scheduled for I 1998 ad 2000, there is o effect of the project-level itegratio o VMT-WZ because o adjacet projects are scheduled for these years. Over the 5-year program ( ), project-level itegratio reduces the total VMT-WZ by about 20% (191,900,000 versus 236,600,000). Project-level itegratio is performed usig spatial aalysis capabilities of GIS. For example, the map show i Fig. 8 idetifies adjacet projects scheduled for implemetatio i 1996 that should be implemeted i a coordiated maer. SUMMARY AND CONCLUSIONS A prototype methodology was developed for the maagemet of various highway ifrastructure compoets i a coordiated ad comprehesive maer at the etwork ad project implemetatio levels. The methodology is, i priciple, applicable to ay umber of highway ifrastructure compoets. A GIS-based ifrastructure maagemet software system was developed usig the cocepts of the ew itegrated methodology. Key features of the ew methodology iclude (1) ivestmet trade-offs (etwork-level itegratio); (2) coordiatig the implemetatio of highway ifrastructure improvemet projects (project-level itegratio); (3) comprehesive evaluatio of highway ifrastructure performace (multiple cocers ad performace measures); ad (4) a sigle system architecture software that ties together the data ad egieerig, ecoomic, ad spatial aalytical procedures. Applyig the methodology to the state highway system i Champaig Couty i cetral Illiois showed that itegratio is beeficial to highway users ad agecies. Over a 5-year program ( ), project-level itegratio reduces the total VMT-WZ by about 20% (191,900,000 versus 236,600,000). GIS, particularly whe usig dyamic segmetatio, is a powerful tool for (1) itegratig, maagig, ad displayig trasportatio data; (2) displayig the geographic distributio of improvemet projects ad deficiet features; (3) displayig spatial relatioships amog performace measures; ad (4) spatially aalyzig trasportatio data. Various aalytical procedures were itegrated with GIS to perform egieerig ad ecoomical aalyses i additio to spatial aalysis ad visualizatio. APPENDIX. REFERENCES Basu, A., ad Batra, R. (1984). Adsplit: A advertisig budget allocatio model. BEBR, Facu. Workig Paper No. 1019, Coll. of Commerce ad Busiess Admi., Uiversity of Illiois at Urbaa-Champaig, Urbaa, Ill., Gharaibeh, N. G. (1997). Improvig highway ifrastructure maagemet practices usig GIS ad optimizatio techiques, PhD thesis, Uiversity of Illiois at Urbaa-Champaig, Urbaa, Ill. Gharaibeh, N. G., Hicks, J. E., ad Hall, J. P. (1997). Aalysis of accidets, traffic, ad pavemet data. Proc., Traffic Cogestio ad Traffic Safety i the 21st Cetury, R. F. Beekohal, ed., ASCE, Resto, Va., Grigg, N. S. (1988). Ifrastructure egieerig ad maagemet. Wiley, New York. Harper, W., ad Majidzadeh, K. (1993). Itegrated pavemet ad bridge maagemet optimizatio. Trasp. Res. Rec. 1397, Trasportatio Research Board, Washigto, D.C., Lee, H., ad Deighto, R. (1995). Developig ifrastructure maagemet systems for small public agecy. J. Ifrastruct. Sys., ASCE, 1(4), Mäistö, V., ad Tapio, R. (1994). Ifrastructure maagemet system: Case study of the Fiish Natioal Road Admiistratio. Trasp. Res. Rec. 1455, Trasportatio Research Board, Washigto, D.C., JOURNAL OF INFRASTRUCTURE SYSTEMS / JUNE 1999 / 67

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