There is a need to develop efficient multi-hazard performance based design (PBD) tools to analyze and optimize buildings at a preliminary stage of design. The first step was to develop a database and it is supported by five major contributions: 1) development of nomenclature of variables in PBD; 2) creation of mathematical model to fit data; 3) collection of data; 4) identification of gaps and methods for filling data in PBD; 5) screening of soil, foundation, structure, and envelope (SFSE) combinations.. A unified nomenclature was developed with the collaboration of a multi-disciplinary team to navigate through the PBD. A mathematical model for incremental dynamic analysis was developed to fit the existing data in the database in a manageable way. Three sets of data were collected to initialize the database: 1) responses of structures subjected to hazard; 2) fragility curves; 3) consequence functions. Fragility curves were critically analyzed to determine the source and the process of development of the curves, but structural analysis results and consequence functions were not critically analyzed due to lack of similarities between the data and background information respectively. Gaps in the data and the methods to fill them were identified to lay out the path for the completion of the database. A list of SFSE systems applicable to typical midrise office buildings was developed. Since the database did not have enough data to conduct PBD calculations, engineering judgement was used to screen SFSE combinations to identify the potential combinations for detailed analysis. Through these five contributions this thesis lays the foundation for the development of a database for multi- hazard PBD and identifies potential future work in this area. / Master of Science

With the increased push towards performance-based engineering (PBE) design, there is a need to understand and design more resilient building envelopes when subjected to natural hazards. Since architectural glass curtain walls (CW) have become a popular façade type, it is important to understand how these CW systems behave under extreme loading, including the relationship between damage states and loading conditions. This study subjects 3D computational models of glass CW systems to in- and out-of-plane loading simulations, which can represent the effects of earthquake or hurricane events. The analytical results obtained were used to support fragility curve development which could aid in multi-hazard PBE design of CWs. A 3D finite element (FE) model of a single panel CW unit was generated including explicit modeling of the CW components and component interactions such as aluminum-to-rubber constraints, rubber-to-glass and glass-to-frame contact interactions, and semi-rigid transom-mullion connections. In lieu of modeling the screws, an equivalent clamping load was applied with magnitude based on small-scale experimental test results corresponding to the required screw torque. This FE modeling approach was validated against both an in-plane racking displacement test and out-of-plane wind pressure test from the literature to show the model could capture in-plane and out-of-plane behavior effectively. Different configurations of a one story, multi-panel CW model were generated and subjected to in- and out-of-plane simulations to understand CW behavior at a scale that is hard to test experimentally. The structural damage states the FE model could analyze included: 1) initial glass-to-frame contact; 2) glass/frame breach; 3) initial glass cracking; 4) steel anchor yielding; and 5) aluminum mullion yielding. These were linked to other non-structural damage states related to the CW's moisture, air, and thermal performance. Analytical results were converted into demand parameters corresponding to damage states using an established derivation method within the FEMA P-58 seismic fragility guidelines. Fragility curves were then generated and compared to the single panel fragility curves derived experimentally within the FEMA P-58 study. The fragility curves within the seismic guidelines were determined to be more conservative since they are based on single panel CWs. These fragility curves do not consider: the effects of multiple glass panels with varying aspect ratios; the possible component interactions/responses that may affect the extent of damages; and the continuity of the CW framing members across multiple panels. Finally, a fragility dispersion study was completed to observe the effects of implementing the Derivation method or the Actual Demand Data method prescribed by FEMA P-58, which differ on how they account for different levels of uncertainty and dispersion in the fragility curves based on analytical results. It was concluded that an alternative fragility parameter derivation method should be implemented for fragility curves based on analytical models, since this may affect how conservative the analytically based fragility curves become at a certain probability of failure level. / Master of Science / Performance-based engineering (PBE) can allow engineers and building owners to design a building envelope for specific performance objectives and strength/serviceability levels, in addition to the minimum design loads expected. These envelope systems benefit from PBE as it improves their resiliency and performance during natural multi-hazard events (i.e. earthquakes and hurricanes). A useful PBE tool engineers may utilize to estimate the damages an envelope system may sustain during an event is the fragility curve. Fragility curves allow engineers to estimate the probability of reaching a damage state (i.e. glass cracking, or glass fallout) given a specified magnitude of an engineering demand parameter (i.e. an interstory drift ratio during an earthquake). These fragility curves are typically derived from the results of extensive experimental testing of the envelope system. However, computational simulations can also be utilized as they are a viable option in current fragility curve development frameworks. As it’s popularity amongst owners and architects was evident, the architectural glass curtain wall (CW) was the specific building envelope system studied herein. Glass CWs would benefit from implementing PBE as they are very susceptible to damages during earthquakes and hurricanes. Therefore, the goal of this computational research study was to develop fragility curves based on the analytical results obtained from the computational simulation of glass CW systems, which could aid in multi-hazard PBE design of CWs. As v opposed to utilizing limited, small experimental data sets, these simulations can help to improve the accuracy and decrease the uncertainties in the data required for fragility curve development. To complete the numerical simulations, 3D finite element (FE) models of a glass CW system were generated and validated against experimental tests. 11 multi-panel CW system configurations were then modeled to analyze their effect on the glass CW’s performance during in-plane and out-of-plane loading simulations. These parametric configurations included changes to the: equivalent clamping load, glass thickness, and glass-to-frame clearance. Fragility curves were then generated and compared to the single panel CW fragility curves derived experimentally within the FEMA P-58 Seismic Fragility Curve Development study. The fragility curves within FEMA P-58 were determined to be more conservative since they are based on single panel CWs. These fragility curves do not consider: the effects of multiple glass panels with varying aspect ratios; the possible component interactions/responses that may affect the extent of damages; and the continuity of the CW framing members across multiple panels. Finally, a fragility dispersion study was completed to observe the effects of implementing different levels of uncertainty and dispersion in the fragility curves based on analytical results.

This dissertation focused on the new performance-based teacher evaluation system implemented in the Commonwealth of Virginia. Eight school districts were granted an implementation waiver for one year making the 2013-2014 school year the implementation year for those school districts. A mixed methodology study was designed to understand teacher perceptions in one waiver school district in the Commonwealth of Virginia. The purposes of this study were to collect empirical evidence on the implementation of the new performance-based teacher evaluation system by comparing teachers' and principals' perceptions at three elementary schools to teachers' perceptions in the school district, identified as District Z and were to add to the research base on policy implementation theories and teacher evaluation. Findings and analysis of research questions were based on the responses of 357 teacher participants, two district directors, and three principals. Policy implementation research suggested access to resources and support along with an alignment of beliefs and values resulted in more effective implementation practices. Conclusions of this study, while limited to the district studied, suggested professional development on the new performance-based teacher evaluation system, including the Uniform Performance Standards and SMART goals, would provide teachers and principals with the increased knowledge to use as a resource during new implementation phases. Additionally, involvement in the design and modification of the teacher evaluation system would encourage participation and provide opportunities for teachers and principals to develop shared values regarding aspects of the evaluation system. / Ed. D.

Performance based contracting in the transportation arena is a rather recently implemented concept which has a few number of applications in the United States up to date. Nonetheless, the US Department of Transportation has vigorously promoted (by issuing memorandums to be distributed to the Highway Agencies and State Departments of Transportation) the conversion of traditional contracts to performance based contracts to reach a goal of 80% of the service contracts and actions being performance based by the end of fiscal year 2004 (Tomanelli 2003.) Virginia Department of Transportation (VDOT) has been one of the first state agencies that took the initiative of using a performance based contract for the maintenance of a portion of its interstate highway system. This initiative resulted in the establishment of the 'Comprehensive Agreement for Interstate Highway Asset Management Services' between VDOT and a private contractor in 1996 which resulted in the privatization of highway maintenance services. One of the important aspects of this contract related to this research is that it does not encompass any warranty clauses. In other words, the contractor does not provide any warranty to the VDOT for the services it is obligated to undertake. The contract is mute in this subject, making the contractor incur no liability for the underperformance of the maintenance activities. According to this research, this might lead to some cases which VDOT would not be willing to encounter. Just like performance based contracting, the use of warranties in highway contracts in the United States is a quite new concept which mainly dates back to 1995. There are different views possessed by different parties about the possible outcomes of implementing warranties in highway contracts. Nonetheless, this research proposes that the incorporation of warranty clauses into the VDOT issued performance based road maintenance contracts is vital to ensure the quality and durability of the work after the project completion. According to this research, warranty clauses, if developed carefully, give the contractor the motivation to implement superior maintenance practices to improve the overall conditions of the assets during the contract period. This is done in order to lengthen the life of each asset item and achieve the long term performance. Ultimately, the incorporation of warranty clauses is believed to reduce the risk imposed upon VDOT. Within the context of the discussion presented above, this research first illustrates that the complete satisfaction of one of the parties (VDOT) may be in question due to the absence of the warranty clauses within the contract, then lists and explores the benefits that would/may be gained by the incorporation of warranty clauses into the contract, and finally develops a warranty clause template and proposes it to be used in the future performance based road maintenance contracts issued by VDOT. At the bottom line, this study aspires to help the party in question (VDOT) to reduce the risk imposed upon it and to improve the future performance based road maintenance contracts it will issue. This research uses the VDOT contract as a baseline to define the problem and to propose a solution (i.e. the developed warranty clause template) for that. Nonetheless, some of the principles and approaches used during the development of the warranty clause template can also be referred to for the development of warranty clauses for the performance based road maintenance contracts issued by the other state DOTs. / Master of Science

A Engenharia de Ventos Baseada em Desempenho (Performance-based Wind Engineering - PBWE) é uma filosofia de projeto que preconiza identificar e quantificar as incertezas envolvidas no projeto estrutural a fim de assegurar níveis previsíveis de desempenho às edificações, não mais gerenciando o risco através da clássica abordagem determinística. Contudo, devido à recente proposição da metodologia, ainda há poucos estudos relacionados à PBWE, cada qual apresentando diferentes limitações. Assim, o presente trabalho propõe uma adaptação da metodologia da Engenharia de Ventos Baseada em Desempenho à análise probabilística do comportamento de torres metálicas, avaliando diferentes modelos de cálculo para estimativa das forças do vento neste tipo de estrutura. Para tanto, investigou-se as incertezas envolvidas na caracterização do campo de ventos e da resistência estrutural e foram analisados quatro métodos distintos para a estimativa das forças de vento em torres metálicas: dois procedimentos de cálculo correspondentes à norma brasileira de ventos ABNT NBR 6123:1988 (ABNT, 1988), a metodologia de Davenport (1993) e a de Holmes (1994). Um estudo de caso envolvendo a estimativa da confiabilidade de uma torre de telecomunicação também foi conduzido. Constatou-se que ambos os procedimentos de cálculo admitidos conduzem a níveis de segurança de mesma ordem de grandeza e que a elaboração de projetos de torres considerando a direção de incidência do vento como sendo a mais desfavorável à estrutura é demasiadamente conservadora. Como contribuição, verifica-se que o projeto ótimo de torres pode ser alcançado com base no nível de segurança desejado para diferentes velocidades máxima de vento associadas a intervalos de recorrência específicos. / Performance-based Wind Engineering (PBWE) is a design philosophy that aims to identify and quantify the uncertainties involved in the structural design in order to ensure predictable performance levels to buildings, no longer managing risk through the classical deterministic approach. However, due to the recent proposal of the methodology, there are few studies related to PBWE, each presenting different limitations. Thus, this paper proposes an adaptation of the Performance-based Wind Engineering methodology to the probabilistic analysis of the behavior of steel towers, evaluating different calculation models for estimating wind forces on this type of structure. To this end, uncertainties involved in the characterization of the wind field and structural strength were investigated and four different methods for the estimation of wind forces on steel towers were analyzed: two procedures relative to the Brazilian winds standard ABNT NBR 6123:1988 (ABNT, 1988), and the methodologies of Davenport (1993) and Holmes (1994). A case study concerning the reliability estimation of a telecommunication tower was also conducted. It was found that both assumed calculation procedures lead to security levels of the same order of magnitude and that the design of towers considering that the wind always blows from the worst direction is too conservative. As a contribution, it is found that the optimum design of towers can be achieved based on the desired security level for different maximum wind speeds associated to specific recurrence intervals.

A Engenharia de Ventos Baseada em Desempenho (Performance-based Wind Engineering - PBWE) é uma filosofia de projeto que preconiza identificar e quantificar as incertezas envolvidas no projeto estrutural a fim de assegurar níveis previsíveis de desempenho às edificações, não mais gerenciando o risco através da clássica abordagem determinística. Contudo, devido à recente proposição da metodologia, ainda há poucos estudos relacionados à PBWE, cada qual apresentando diferentes limitações. Assim, o presente trabalho propõe uma adaptação da metodologia da Engenharia de Ventos Baseada em Desempenho à análise probabilística do comportamento de torres metálicas, avaliando diferentes modelos de cálculo para estimativa das forças do vento neste tipo de estrutura. Para tanto, investigou-se as incertezas envolvidas na caracterização do campo de ventos e da resistência estrutural e foram analisados quatro métodos distintos para a estimativa das forças de vento em torres metálicas: dois procedimentos de cálculo correspondentes à norma brasileira de ventos ABNT NBR 6123:1988 (ABNT, 1988), a metodologia de Davenport (1993) e a de Holmes (1994). Um estudo de caso envolvendo a estimativa da confiabilidade de uma torre de telecomunicação também foi conduzido. Constatou-se que ambos os procedimentos de cálculo admitidos conduzem a níveis de segurança de mesma ordem de grandeza e que a elaboração de projetos de torres considerando a direção de incidência do vento como sendo a mais desfavorável à estrutura é demasiadamente conservadora. Como contribuição, verifica-se que o projeto ótimo de torres pode ser alcançado com base no nível de segurança desejado para diferentes velocidades máxima de vento associadas a intervalos de recorrência específicos. / Performance-based Wind Engineering (PBWE) is a design philosophy that aims to identify and quantify the uncertainties involved in the structural design in order to ensure predictable performance levels to buildings, no longer managing risk through the classical deterministic approach. However, due to the recent proposal of the methodology, there are few studies related to PBWE, each presenting different limitations. Thus, this paper proposes an adaptation of the Performance-based Wind Engineering methodology to the probabilistic analysis of the behavior of steel towers, evaluating different calculation models for estimating wind forces on this type of structure. To this end, uncertainties involved in the characterization of the wind field and structural strength were investigated and four different methods for the estimation of wind forces on steel towers were analyzed: two procedures relative to the Brazilian winds standard ABNT NBR 6123:1988 (ABNT, 1988), and the methodologies of Davenport (1993) and Holmes (1994). A case study concerning the reliability estimation of a telecommunication tower was also conducted. It was found that both assumed calculation procedures lead to security levels of the same order of magnitude and that the design of towers considering that the wind always blows from the worst direction is too conservative. As a contribution, it is found that the optimum design of towers can be achieved based on the desired security level for different maximum wind speeds associated to specific recurrence intervals.

Performance-based contracting (PBC) redefines the relationships between suppliers and buyers and differs from traditional contracting approaches with its reward/payment scheme, emphasis on the performance outcomes, increased supplier autonomy, and transfer of risk and responsibilities to suppliers. Given the 70% of life cycle costs of products/systems reside in sustainment, PBC has led to substantial improvements in availability, maintainability, reliability, and thus total cost of ownership of systems/products. Though PBC has changed the way of doing business and its presence has increased across multiple industry, private and public sectors, for profit and not-for-profit, its implications on various aspects of logistics and supply chain management have been understudied. It is important to explore and establish evidence regarding these implications through academic rigor. Therefore, this three-essay dissertation aims to give some insight regarding structural and behavioral implications of PBC using a multi-method approach. Specifically, it (1) explores the relationship between PBC and supply chain resilience (SCRES), (2) examines the supplier goal commitment (i.e., motivation) in PBC, (3) proposes a mathematical model to find optimal contract length, periodic contract price and investment that concurrently maximizing supplier profit and satisfying buyer requirements. This dissertation offers theoretical and managerial contributions as well.

Master of Science / Department of Architectural Engineering and Construction Science / Kimberly W. Kramer / The basic tenets of performance based seismic design (PBSD) are introduced. This includes a description of the underlying philosophy of PBSD, the concept of performance objectives, and a description of hazard levels and performance indicators. After establishing the basis of PBSD, analysis procedures that fit well within the PBSD framework are introduced. These procedures are divided into four basic categories: linear static, linear dynamic, nonlinear static, and nonlinear static. Baseline FEMA requirements are introduced for each category. Each analysis category is then expanded to include a detailed description of and variations on the basic procedure. Finally, optimization procedures that mesh well with a PBSD framework are introduced and described. The optimization discussion focuses first on the solution tools needed to effectively execute a PBSD multi-objective optimization procedure, namely genetic and evolutionary strategies algorithms. Next, multiple options for defining objective functions and constraints are presented to illustrate the versatility of structural optimization. Taken together, this report illustrates the unique aspects of PBSD. As PBSD moves to the forefront of design methodology, the subjects discussed serve to familiarize engineers with the advantages, possibilities, and finer workings of this powerful new design methodology.

Στην παρούσα εργασία παρουσιάζεται μία νέα βασισμένη στην επιτελεστικότητα μέθοδος αντισεισμικού σχεδιασμού χωρικών μεταλλικών κατασκευών, οι οποίες υπόκεινται σε σεισμικές διεγέρσεις μακρινού πεδίου. Η μέθοδος αυτή συνδυάζει τα πλεονεκτήματα της μεθόδου σχεδιασμού με βάση τις δυνάμεις και με βάση της μετατοπίσεις και γι’ αυτό ονομάζεται υβριδική δυνάμεων-μετατοπίσεων (ΥΔΜ) μέθοδος. Για τη δημιουργία της προτεινόμενης μεθόδου γίνεται παραμετρική σεισμική μελέτη κανονικών καμπτικών μεταλλικών κτιρίων με και χωρίς τυχηματικές εκκεντρότητες, καθώς και μεταλλικών κτιρίων τα οποία εμφανίζουν γεωμετρικές μη κανονικότητες λόγω ανομοιόμορφης καθ’ ύψος κατανομής μάζας και λόγω παρουσίας εσοχών. Αρχικά γίνεται μια βιβλιογραφική ανασκόπηση για τις ήδη υπάρχουσες μεθόδους, όσον αφορά στο σχεδιασμό και στην εκτίμηση της ανελαστικής σεισμικής απόκρισης επίπεδων και χωρικών κατασκευών. Στη συνέχεια περιγράφεται η επιλογή των παραμέτρων και η όλη διαδικασία που ακολουθήθηκε για τη δημιουργία μίας βάσης δεδομένων σεισμικής απόκρισης η οποία απαίτησε 43176 μη γραμμικές δυναμικές αναλύσεις. Με βάση την στατιστική επεξεργασία που έγινε προέκυψαν εμπειρικές σχέσεις αντισεισμικού σχεδιασμού, οι οποίες καθιστούν δυνατό τον έλεγχο της βλάβης κατά το σχεδιασμό νέων κατασκευών και οι οποίες λαμβάνουν υπόψη την επιρροή διαφόρων παραμέτρων, όπως ο αριθμός ανοιγμάτων, ο αριθμός ορόφων, η μορφή της κάτοψης, καθώς και η μη κανονικότητα της κατασκευής. Επιπλέον εξετάστηκε η επιρροή της φυσικής μονοαξονικής εκκεντρότητας, μεταξύ κέντρου μάζας και κέντρου δυσκαμψίας στην ανελαστική σεισμική απόκριση χωρικών κατασκευών με μεικτό σύστημα ανάληψης σεισμικών δυνάμεων. Ωστόσο, επειδή ο αριθμός των κτιρίων που χρησιμοποιήθηκαν ήταν μικρός, δεν έγινε προσπάθεια κατασκευής κάποιων εμπειρικών σχέσεων από τα αποτελέσματα που προέκυψαν για αυτήν την περίπτωση. Τα πλεονεκτήματα της νέας ΥΔΜ μεθόδου αντισεισμικού σχεδιασμού, παρουσιάζονται μέσω τριών παραδειγμάτων, όπου η προτεινόμενη μέθοδος συγκρίνεται με τη μέθοδο σχεδιασμού με βάση τις δυνάμεις στην οποία βασίζονται όλοι σχεδόν οι υπάρχοντες αντισεισμικοί κανονισμοί. Από τη σύγκριση που γίνεται προκύπτει ότι, σε αντίθεση με τη μέθοδο των δυνάμεων, η ΥΔΜ μέθοδος μπορεί να κάνει κατά το σχεδιασμό άμεσο έλεγχο της βλάβης. / This dissertation proposes a preliminary performance-based seismic design method for three-dimensional steel building frames under ordinary (i.e., without near fault effects) ground motions. This method combines the advantages of the well-known force-based and displacement-based seismic design methods in a hybrid force/displacement design scheme. The proposed method was developed based on the results of an extensive parametric study involving the inelastic seismic response of regular and irregular moment resisting frames (MRFs). The regular MRFs are structures with and without the presence of accidental eccentricities, whereas the irregular MRFs, are structures with vertical mass irregularities and structures with setbacks. In total 146 buildings have been studied. The results of 43176 nonlinear dynamic analyses were post-processed in order to create a databank with the response quantities of interest. The main parameters that affect the inelastic response of the examined structures were recognised after the statistical analysis of the created response. Based on regression analysis, a procedure in terms of simple formulae for estimating the maximum roof displacement, the maximum interstorey drift ratio and the maximum rotation ductility along the height of the frame was developed. In addition, the inelastic seismic response of 20 buildings with natural eccentricities has been studied, which combines MRFs with buckling restrained braces. However, the conclusions of this case cannot be generalized, because only few cases were investigated. Comparison of the proposed method with the procedures adopted in current seismic design codes demonstrated the efficiency of the former. The results revealed that the proposed procedure seems to be more rational and efficient than the procedures used in the current seismic design codes. Nonlinear time history analyses proved the consistency of the proposed method to accurately estimate inelastic deformation demands and the tendency of the current seismic design codes to overestimate the maximum roof displacement and underestimate the maximum interstorey drift ratio along the height of the frames.

A qualidade dos sistemas de sinalização viária é avaliada, tradicionalmente, com base nas características físicas de seus elementos, bem como na durabilidade e conservação dos materiais que os compõem. Em alguns casos, a verificação do atendimento aos critérios técnicos de projeto é também considerada. Depreende-se, daí, que a avaliação estrutural dos elementos de sinalização seja integralmente contemplada por meio dessas avaliações. Por outro lado, a eficácia da sinalização não é necessariamente garantida pela integridade física ou estrutural dos elementos. Por se tratar de um sistema de comunicação com o usuário, que transmite informações que influenciarão as ações dos motoristas na tarefa de guiar o veículo no trânsito, é necessário, também, avaliar o desempenho funcional dos elementos de sinalização. Em outras palavras, o funcionamento e a eficiência da sinalização são tão importantes quanto a situação de seu estado físico. Esta pesquisa descreve aspectos a serem considerados na avaliação de desempenho funcional dos sinais de trânsito com base na observação no campo e na abordagem dos fatores que afetam as medidas de desempenho, conduzindo, em rodovias federais brasileiras concedidas à iniciativa privada, dois experimentos ainda pouco conhecidos no país. O primeiro experimento avaliou o desempenho de um conjunto de placas de sinalização de regulamentação de velocidade máxima permitida, aplicadas em configurações diversas. As medidas de desempenho escolhidas foram a distância de detecção e a distância de legibilidade da sinalização, que foram medidas por meio de observadores em curso na rodovia, em condições reais de operação. O segundo experimento avaliou o desempenho de um conjunto de demarcações no pavimento de uma rodovia também em condições reais de operação. A medida de desempenho foi a retorrefletividade da sinalização horizontal sob tráfego real. A pesquisa inova ao utilizar o conceito de planejamento de experimentos, otimizando o modelo estatístico a ser estimado com menos execuções experimentais. / The quality of the traffic signs systems is traditionally assessed based on physical characteristics of their elements, as well as the durability and conservation of materials they are made of. In some cases, the verification of compliance with the technical criteria for design is also considered. Therefore, it appears that the structural assessment of sign elements is fully covered by these evaluations. Moreover, the effectiveness of traffic signs is not necessarily guaranteed by physical or structural health of the elements. Once the traffic signs comprise a system of communication with the users, which gives information that will influence the actions of the drivers on the task of guiding the vehicle in traffic flow, it is also necessary to evaluate the functional performance of the traffic signs. In other words, the operation and efficiency of traffic signs are as important as their physical condition. This research describes some aspects to take into account in the evaluation of performance of traffic signs based on observation in the field and in the approach of the factors affecting performance measures, carrying out in Brazilian federal highways under concession to the private sector two experiments still little known in this country. The first experiment evaluated the performance of a set of speed limit signs applied in different configurations. The chosen performance measures were the detection distance and the legibility distance of the signs, which were measured by subjects driving on open road under real operating conditions. The second experiment evaluated the performance of a set of pavement markings also on open road under real operating conditions. The performance measure was the retroreflectivity of the pavement markings under real traffic. The survey breaks new ground by using the concept of optimal design of experiments, optimizing the statistical model to be estimated with fewer experimental runs.