Transportation infrastructure improvement projects are typically huge and have significant economic and environmental effects. Forecasts of demand of the facility in the form of traffic level help size the project as well as choose between several alternatives. Inaccuracy in these forecasts can thus have a great impact on the efficiency of the operational design and the benefits accrued from the project against the cost. Despite this understanding, evaluation of traffic forecast inaccuracy has been too few, especially for un-tolled roads in the United States. This study, part of a National Cooperative Highway Research Program (NCHRP) funded project, bridges this gap in knowledge by analyzing the historical inaccuracy of the traffic forecasts based on a database created as part of the project. The results show a general over-prediction of traffic with actual traffic deviating from forecast by about 17.29% on an average. The study also compares the relative accuracy of forecasts on several categorical variables. Besides enumerating the error in forecasts, this exploration presents the potential factors influencing accuracy. The results from this analysis can help create an uncertainty window around the forecast based on the explanatory variables, which can be an alternate risk analysis technique to sensitivity testing.

The transport infrastructure facilitates the development of national economies not only in Europe but all over the world. Stagnating transport network development, along with stagnating modernisation of such networks caused by a lack of funds and associated with the absence of modern approach and technology within the construction and operation, has a fatal impact on the advancement of trade, industry and, ultimately, the development of the state itself. The dissertation thesis aims to describe and verify the way the heavy road infrastructure development supports the economy of the whole country, regions and economic entities. At the same time, the thesis strives to examine whether the construction completion accelerates the development and building of logistic centres in the vicinity of such big highways, and the manner the commissioning of such buildings is reflected in traffic intensity changes inland and at the borders.

The objective of this thesis is to study the sources of discrepancy between the actual traffic in motorways under concession schemes and the traffic forecast ex-ante. The demand forecast for a specific project is the main variable influencing its realization. From a public sector perspective, socio-economic evaluations are driven by demand forecasts, which gives the basis for choose and hierarchy public projects in order to maximise social welfare. From a private sector perspective, traffic forecasts are the base of financial evaluation and toll setting.Despite its importance and the numerous and important developments in the field, the differences of forecast and ex-post traffic are usually very high. Some recent studies show that differences as big as 20% are much more the rule than the exception.A huge amount of uncertainty is associated with the forecasting exercise. First because transport is a derived demand and depends on many exogenous variables, also uncertain; because modelling is and simplification exercise, implies many assumptions and rely on field data, many times incomplete or of low quality; moreover, modelling human (in this case users) behaviour is always a dangerous enterprise.Although these arguments could explain at least the larger part of errors associated with forecasts, one can wonder whether the agents implicated in the forecast would or could use this uncertainty strategically in their favour. In a competition for the field scheme (bids), the bidder may overestimate the demand in order to reduce the toll included in the bid. This strategic behaviour can introduce a high bias in forecasts. Also, overoptimistic (or overpessimistic) forecasters may introduce a bias in the forecast.We propose to focus in turn on the three main groups of agents involved in the demand forecast process. The forecasters, the project promoters and the users. Study all the issues related to them would be a too ambitious (or more concretely impossible) task. We then focus on some particular issues related to the modelling of the actors' behaviour in the context of the demand forecast for toll roads.Regarding the forecaster behaviour, we present the results of the first large sample survey on forecasters' perceptions and opinions about forecasting demand for transport projects, based on an on-line survey. We first describe the main characteristics of forecasters. We then describe the last forecast forecasters prepared. We turn to the models forecasters apply, the errors they declare on past forecasts and the main sources of errors according to them. We then describe the forecast environment in terms of pressure forecasters receive. These unique results provide a picture of the world of forecasters and forecasts, allowing for a better understanding of them. We turn then to the study of the optimism and overconfidence in transport forecasts. Optimism and overconfidence in general are recognized human traits. We analyze the overoptimistic bias by comparing the distribution of stated errors with actual errors found in literature; we also compare the own skilful of subjects in doing forecasts with studies showing self-evaluations of a common skill - driving. We finally propose a regression of the competence, quality and errors on the main forecasters' and projects' specific variables.Results show that the distribution of errors transport forecasters state has a smaller average magnitude and a smaller variance than those found in literature. Comparing forecasters perception of their own competence with the results found in literature about drivers skill self-evaluation, however, we could not find a significant difference, meaning that the forecasters' overconfidence is in line with what could be viewed as a normal human overconfidence level.The pressure for results forecasters receive and the strategic manipulation they affirm exist merit a special attention. They imply that while forecasters' behavioural biases may exist and should be take in account when evaluation forecasts, the project promoter may influence forecasts by pressuring the forecasters to produce results which better fit his expectancies.We then study the bidders' strategic behaviour in auctions for road concessions. We address three questions in turn. First, we investigate the overall effects of the winner's curse on bidding behaviour in such auctions. Second, we examine the effects of the winner's curse on contract auctions with differing levels of common-value components. Third, we investigate how the winner's curse affects bidding behaviour in such auctions when we account for the possibility for bidders to renegotiate. Using a unique, self-constructed, dataset of 49 worldwide road concessions, we show that the winner's curse effect is particularly strong in toll road concession contract auctions. Thus, we show that bidders bid less aggressively in toll road concession auctions when they expect more competition. We observe that this winner's curse effect is even larger for projects where the common uncertainty is greater. Moreover, we show that the winner's curse effect is weaker when the likelihood of renegotiation is higher. While the traditional implication would be that more competition is not always desirable when the winner's curse is particularly strong, we show that, in toll road concession contract auctions, more competition may be always desirable. Modelling aggregated users' behaviour, we study the long term traffic maturity. We argue that traffic maturity results from decreasing marginal utility of transport. The elasticity of individual mobility with respect to the revenue decreases after a certain level of mobility is reached. In order to find evidences of decreasing elasticity we analyse a cross-section time-series sample including 40 French motorways' sections. This analysis shows that decreasing elasticity can be observed in the long term. We then propose a decreasing function for the traffic elasticity with respect to the economic growth, which depends on the traffic level on the road. Although “unconditional” decreasing elasticities were already proposed in the literature, this is the first work, as far as we know, putting this idea in evidence and giving it a functional form. This model provides better interpretation of the coupling between traffic and economic growth, and a better long-term forecast. From the disaggregate perspective, we study the main individual modal choice variable, the value of time. The value of travel time savings is a fundamental concept in transport economics and its size strongly affects the socio-economic evaluation of transport schemes. Financial assessment of tolled roads rely upon the value of time as the main (or even the unique) willingness to pay measure. Values of time estimates, which primarily represent behavioural values, as then increasingly been used as measures of out-of-pocket money. In this setting, one of the main issues regarding the value of time is its distribution over the population. We apply the Logit, the Mixed Logit and the Bayesian Mixed Logit models to estimate the value of time in freight transport in France. Estimations with mixed logit faced many difficulties, as expected. These difficulties could be avoided using the Bayesian procedures, providing also the opportunity of properly integrating a priori beliefs. Results show that 1) using a single constant value of time, representative of an average, can lead to demand overestimation, 2) the estimated average value of time of freight transport in France is about 45 Euro, depending on the load/empty and hire/own account variables, which implies that 3) the standard value recommended in France should be reviewed upwards.

The subject of this diploma thesis is variant design of adaptation of T- intersection to crossroad at Frýdek-Místek. At first, there was made traffic forecast of generated traffic from regional planning. After that, there were made traffic forecast from relocation of road II/477. Then for every traffic forecast there were made two more variants of designs. The first variant is designed by one lane roundabout and signal-controlled intersection with signal timing plan. The second and the third variant are designed by turbo roundabout and signal-controlled intersection with signal timing plan. All variants have their own capacity analysis.

Luftverkehrsprognosen stellen ein wichtiges Instrument dar, die Luftverkehrsinfrastruktur zu beeinflussen. Hinter vielen der Projekte, die von Luftverkehrsprognosen begleitet werden, stehen Interessen. Dies gilt insbesondere für Ausbauvorhaben von Flughäfen, die von eindeutigen Zielen und Wünschen getragen werden. Die Gutachter, die im Rahmen solcher Ausbauvorhaben tätig werden, sind der Gefahr ausgesetzt, beeinflusste Prognosen zu erstellen. Die Art und Intensität dieser Beeinflussung sowie die Methodik dieser Analysen sind Gegenstand dieses Aufsatzes. Zunächst wurden neuere Ergebnisse der OECD und EU erarbeitet und denen der Flughafenstudien gegenübergestellt. Nachfolgend wurde die Intensität der Beeinflussung auf Grundlage einer eigenen Untersuchung analysiert. Dabei wurden politische Entscheidungsträger im Rhein-Main-Gebiet nach Ihrer Verwendung von Studien und deren Ergebnisse befragt. Die Impact Study, als häufigste Forschungsmethodik, wurde in ihre Bestandteile zerlegt und mit der Full Cost-Benefit-Analyse, welche die durch die FAA empfohlene Methode ist, verglichen. Grundsätzlich sind solche Gutachten meist externe Analysen aus privatwirtschaftlicher Hand, die einerseits im Auftrag von regionalen Entscheidungsträgern, aber andererseits auch im Auftrag von Flughafen- und Fluggesellschaften angefertigt wurden. Die Unabhängigkeit der Prognosen ist damit gefährdet. Auf Grundlage der (neutralen) OECD- und EU-Ergebnisse zeigte sich, dass etwaige regionale Wirtschaftsimpulse und damit einhergehendes Beschäftigungswachstum durch erhöhten Flugverkehr nicht zu finden sind. Die kritische Analyse von „bezahlten Studien“ ist demnach von Bedeutung. Die Mehrzahl der politischen Amts- und Entscheidungsträger in Deutschland trifft allerdings Entscheidungen auf Basis keiner oder ausschließlich nicht-neutraler, bezahlter Auftragsstudien. Historisch betrachtet ist dies kein Novum. Bereits in den 60er Jahren kann man solche Studien und Entscheidungen nachweisen. Bezüglich des Forschungsdesign zeigte sich, dass Impact-Studien kaum für zur Beurteilung des Luftverkehrs geeignet sind. Sie beziehen die relevanten Effekte nur teilweise in ihre Berechnungen ein. Es wurde eine Reihe von systematischen Fehlern identifiziert. Die FAA-Richtlinien in den USA für methodisch korrekte Studien greifen nur wenig. Für weitere Forschung sehen wir die wichtige Aufgabe, die Methodik der Full Cost-Benefit-Analyse für die Prognose möglicher Effekte zur Anwendung zu bringen. / Aviation traffic forecasts and airport analyses are important instruments which influence decisions on aviation related infrastructure. Behind many of such infrastructure projects, which are supported by forecast analyses, one finds political interests. This is especially the case for aviation projects, such as infrastructure enlargement projects of airports, which are motivated by distinct goals and desires. Referees who act within this framework are exposed to the risk of producing biased results. The form and degree of intensity of such influence and manipulation, as well as the methodology of such forecast analyses, are the subject of this working paper. To begin with, newer research results by the OECD and the EU have been formulated and further compared to results of studies commissioned by airport operators. Subsequently, the degree of intensity of such influence has been analysed on the basis of our own research. A survey was thereby produced, investigating the application of neutral and non-neutral studies in the decision-making processes of the public administration in the Rhein-Main-area. Impact studies, which are currently the most used method, have been segmented and compared with studies using full cost-benefit-analysis, the recommended method by the FAA. With regard to these results, it can be argued that most forecast analyses are produced by private consultancies, by order of public entities but also by order of airport operators. The independence of such research and its results is therefore endangered. Recent OECD and EU research results have shown that eventual effects, such as regional economic stimulus and employment growth, are absent. Thus, care in the application of study results in this field is necessary. However, the majority of policy makers (in Germany) unfortunately base their decisions mostly on non-neutral studies. Historically seen, this is not a novelty. Regarding the research design, impact studies are hardly suitable for airport studies. Further, it can be shown that impact studies incorporate mostly only non-negative items in their cash flow calculations, compared to full cost-benefit-analyses which incorporate all relevant items. A number of systematic flaws are further identified. The regulation-guidelines by the FAA, which demand to incorporate all items, have had little impact on the research design of airport studies in the US so far. The promotion and fostering of full cost-benefit-analyses is necessary to lift the quality of airport studies.