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    <title>Transport Research International Documentation (TRID)</title>
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
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    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Sequential models for the mobility decisions: experimentation for vehicleholding choices</title>
      <link>https://trid.trb.org/View/859851</link>
      <description><![CDATA[The demand models used in literature, in the field of a behavioural approach, generally simulate the user choices through a discrete choices model.The consolidated approach is not explicitly able to simulate the variation of choice probability, in consequence of the different events, which characterize the evolution of transportation system. So, in this note, two types of model are defined: static demand models the models that give the choice probability of the single alternative, independently of the actual choice of the decision-maker, relative to the actual system condition; and dynamic demand models the models that give the choice probability accordingto the actual and the previous system condition, considering change and earlier decisions. The need to introduce dynamic models regards different main decisions, among which it is possible to recall: the path choice, for a private transportation system user; the run choice, for a transit systemuser, considering the travel choices; and the ownership choice and particularly the ownership decision of vehicles, considering the mobility choices. Predominantly, the models used in this area of research are members of the family of discrete choice models, derived from the random utility theory. This theory is based on the hypothesis that every individual is a rational decision maker, maximizing utility relative to his own choices. Different discrete choice models are obtained from different specifications of the joint density of the random vector. The models used in literature are:the Generalized Extreme Value (GEV) model; the Probit model; the ordered GEV model and the Mixed Multinomial Logit model. The most used from researchers and practitioners is the Multinomial Logit model. These mathematicalmodels have been applied in a way that does not represent adequately the dynamic of the choice process, emphasizing the systematic and invariant aspects of choice behaviour, which are assumed to dominate the choice process. In particular, they do not represent explicitly the influences exercised by the previous decisions on the actual choice. In literature, the knownmodels that consider the effects of the previous choices are the car ownership models. Many of these studies simulate the car ownership choices using the Multinomial Logit model and introduce the parameter transaction search cost, in order to consider the influence exercised by the previous choices. A previously developed series of linked choice models to explain household vehicle ownership and adjustments in ownership over time is discussed. The effects of the experience are considered introducing the brand loyalty and the parameter experience index, which is a summary of retrospective utility. The vehicle type choice is simulated using a Mixed MultinomialLogit model. This represents the effects of the experience through the brand loyalty and the random components, and is able to consider their endogeneity. However, these models are based on static (or pseudo-dynamic) structures. The transition matrix, which represents the variation of user decisions over time, and the sequential model, which represent the time dependencies of path choice, has suggested the vehicle transition choice model. According to the sequential approach, the model simulates the permanence or the transition of the actual system state. It is different from the pseudo-dynamic models, because it simulates explicitly the choice of an alternative, in a given period of time, conserving or modifying the choice set relative to the previous period. The time-dependencies are considered introducing some attributes that are function of the past state. At first, the proposed model has been applied to the holding vehicle, in order to compare the results obtained with the experimentation of the pseudo-dynamic models, used in literature. The model has been specified, calibrated and validated using: a database relative to the socio-economic evolution of a sample family, which captures dynamic longitudinal effects; a database relativeto the technical classification of vehicles, defined by a company of car rent; a database relative to the technical-performances characteristics ofvehicles, obtained by a specialized car review published in Italy. The results obtained from the experimentation of the transition model are presented in the paper with the results obtained through the application of the models used in literature. The comparison gives a favourable result for the transition model in relation to the other experimented models. For the covering abstract see ITRD E137145.]]></description>
      <pubDate>Tue, 27 May 2008 09:26:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/859851</guid>
    </item>
    <item>
      <title>Random utility model of pseudo panel and application on car ownership forecast</title>
      <link>https://trid.trb.org/View/859850</link>
      <description><![CDATA[Pseudo panel is a relatively new econometric technique to estimate dynamic models using repeated cross sectional data. This paper reports the recent development on the theoretical aspects of the nonlinear pseudo panel as well as some substantially improved empirical results of the car ownershipmodel. It is organised as follows: The first section discusses the pros and cons of nonlinear pseudo panel model and argue for its potential as an effective third way in modelling and forecasting using cross sectional data. Compared with the conventional cross sectional model, the nonlinear pseudo panel has the advantages of (1) Consideration of dynamic in modelling;(2) Effective tackling of aggregation bias problem. Its disadvantage are (1) Reduction in data variability; (2) Loss of information on individual decision makers. Compared to its linear counterpart, nonlinear pseudo panelmethod has the advantage of (1) Explicitly modelling and estimating saturation level; (2) Can be formulated to be consistent with theory of utilitymaximization. However, it suffers the limitation of (1) incidental parameter problem for fixed effect model; (2) Needing tailored code for estimating advanced models. On balance, nonlinear pseudo panel model is most suitable for forecasting purpose, and the case is less clear for analytical purpose. Section 2 introduces a random utility model of pseudo panel. In a standard random utility model of cross sectional data, the utility function consists of a deterministic term and a random term. For pseudo panel model, such a deterministic term can be further decomposed into four components: the first is the sample mean observable utility of alternative a for cohort c in year t, which is deterministic and observable; the second is the difference between the sample mean utility and the true mean unobservable utility of alternative a for cohort c in year t, which represents the measurement error; the third is the (time-invariant) unobserved heterogeneity,which includes alternative specific constants and cohort fixed (random) effect; the fourth component represents the unobserved utility of alternative a for individual i in year t, which is the deviation from the mean utility for the cohort. It should be noted that the fourth component is observable to researchers in the cross-sectional models and is lost in the aggregation process of pseudo panel. The fourth decomposed utility component has to be combined with the random utility term in the underlying cross sectional model; consequently the two types of model have different scales. For dynamic model, if there is true state dependence, the choice from the previous period will affect the current utility and it is natural to includethe lagged dependent variable in the utility function. However, the lagged dependent variable might appear significant even without true state dependence due to unobserved heterogeneity or series correlation. This has to be taken into account in empirical work. Section 3 applies the pseudo panel RUM to car ownership modelling. The hierarchical model structure for handling multiple car ownership has been chosen. This model is then extended to take saturation into account. To be consistent with the RUM theory, a Dogit model structure is adopted; this model also ensures the saturation level can be reliably estimated and statistically tested. Section 4 discusses the consistent estimation of the pseudo panel RUM. The fixed effect estimator is consistent only when the number of time period is sufficiently large, while the random effect estimator requires that the unobserved heterogeneity are uncorrelated with the explanatory variables. The mixed logit model allows all the parameters to be random, thus make the orthogonality assumptions of the random effect model rather irrelevant. Section 5 reportsthe empirical results of car ownership model. Separate results are presented for models of one plus cars and those of two plus cars. Selected results for static fixed effect models, random effect models, dynamic fixed effect model, random parameters (mixed logit) models, and Dogit models will be reported. Section 6 uses the preferred econometric model to forecast thelevel of car ownership in Great Britain to year 2026. Results will be compared to the observed data in the early forecast years and forecasts from other published studies of car ownership. For the covering abstract see ITRD E137145.]]></description>
      <pubDate>Tue, 27 May 2008 09:26:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/859850</guid>
    </item>
    <item>
      <title>Model of weekly working participation for a Belgian synthetic population</title>
      <link>https://trid.trb.org/View/859849</link>
      <description><![CDATA[The work patterns of individuals or households continue to provide a major determinant in daily mobility, even if a number of recent contributions indicate that it is not, or no longer, the only critical one. The purpose of this study is to focus on the patterns structure, and to consider the construction of the household work pattern as a piece of the household activity scheduling. However, if one restricts the scope to daily patterns scheduling, then the number of useful distinctions shrinks considerably and often boils down to the distinction between full-time and part-time work, with possible consideration for industrial work shifts, or questions about who is responsible for the organization of the working hours (MOBEL). However, analysis of the existing data on work pattern structure indicates that there is considerable variation from day to day, and that variations across individuals are also correlated to variations over the days. It is considered that the global view of work trips, tours or chains can hardly be realistically apprehended if one limits oneself to the daily and individual view. An attempt to extend the analysis of the household work patterns to a weekly horizon, rather than the most common daily one, is presented. This weekly pattern is considerably more adapted to the description of the observed variability, although even longer cycles such as those depending on seasons or annual holidays could be considered. To cover the Belgian national territory and to capture the behavioural differences existing across the three Regions (Brussels, Walloon Region, Flemish Region), three sources of data were used. The three surveys, called MOBEL, ERMM and OVG, wereall conceived as travel diary and held between 1999 and 2003. MOBEL and ERMM databases store information on a daily basis, while the OVG survey contains trips data over two days of the same weeks. It is acknowledged that this way to proceed cannot account for differences among working participation programs across the week. A project to collect travel diary over a week is currently under evaluation in Belgium. A model is proposed, based ona utility maximizing principle and assumes a weekly cycle for a householdworking participation program. The week is divided into seven days time periods. The household can be based on one adult or two adults. Two decision-making processes are applied. For each time period the one adult household can either decides to go to work or not to go to work; in the first case he/she can work part time or full time. The process is more complex for two-adult households; the alternatives are constructed as follow: both components not working; one of them working, the other not working, both working. When working participation is observed then the option of full time and part time involvement is presented. A nested logit structure, is adopted to model this decision process. The variables included are: age divided by categories 18-39/40-59/+60, gender, education (no diploma, elementary, secondary, higher degrees), driving licence, and household type (single with or without children, couple with or without children). The parallel construction of a synthetic population for Belgium is described on this basis. The model calibrated is then applied to the Belgian synthetic populationand the activity participation shares will be compared to those reported in the surveys. A geographic performance is also envisaged; in fact accuracy of the model will be calculated both on regional and national scale. For the covering abstract see ITRD E137145.]]></description>
      <pubDate>Tue, 27 May 2008 09:26:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/859849</guid>
    </item>
    <item>
      <title>Trip-based route choice models - a method to eliminate aggregation bias in activity-based models</title>
      <link>https://trid.trb.org/View/859848</link>
      <description><![CDATA[Activity-based models provide more insight in personal travel behaviour than traditional demand models. The newest types of activity-based models simulate individuals activity patterns over the day, i.e. the fundamental modelling unit is the individual (integer). The insight into the characteristics of each trip is therefore higher; income, value of time (VoT), gender, etc. may be related directly to the individual trip. Especially VoT is interesting, since it may depend on e.g. the persons income, the time use of the trip (trip length), the trip purpose and the time of the day. Individual-based disaggregate approaches are different from traditional matrix-based models (whether activity-based or not), where the fundamental unit is the cell in the matrices and the unit is a floating point. With the increasingly segmentation of models into time-of-day, trip purposes and numberof zones, the size of this fundamental unit may be quite small often evenmuch lower than on average. An example is the Copenhagen model (OTM), where there are 2.2 million car trips, distributed between 835×825 zones, 7 time-periods and 6 trip purposes. This equals 42 trip matrices and 0.07 trips in average per cell. Activity-based models are often used to evaluate network effects, where the VoT may be a core element in the decision making. An example is congestion reducing projects or road pricing schemes. The information of the individual trip characteristics from the demand models are however seldom used directly in the assignment procedures. Hence, a frequently used approach is that the detailed trips from the activity-based models are aggregated to zones and trip matrices, which are then assigned by traditional assignment procedures. The level of service (LoS) matrices produced by the assignment procedure are hereby only an average. There aretherefore both socio-economic and geographic aggregation bias. This is relatively larger for short trips due to the zonal aggregation of the start and end point of the trip. The problem of aggregation bias may be solved partly by segmenting the demand into more trip purposes and VoT intervals, and carry out a multi-purpose assignment. This increase however the numberof matrices and reduce the cell-sizes further. In the case of the Copenhagen model, 5 VoT intervals would increase the number of car matrices from 42 to 210, and the average cell-size would be reduced from 0.07 to 0,015. If the trips are also to be split into trip-length segments, this will increase the number of matrices further, and also introduce a need of sortingthe matrices at cell-level before the splitting. Therefore, an intuitive improvement of assignment procedures in activity-based modelling is to assign the trips directly onto the network. The obvious benefits have been described above; Direct use of trip attributes in the assignment, e.g. VoT depending on the individuals income, trip length, trip purpose and time-of-the-day. Correct LoS calculations for feedback from assignment to demand. Another benefit is that there is no need for a zonal aggregation, and the trips can therefore be assigned directly from node to node rather than from zone to zone. The need for zones and zonal connectors are therefore eliminated. The usual problems with too much traffic at the roads near the endof the connectors are hereby eliminated, as well as problems to get the right distribution of traffic onto the different connectors from/to a zone.Trip-based assignment procedures are often claimed to increase calculation time compared to matrix based. However, it is shown that the theoreticalcalculation complexity of trip-based assignment models used within large-scale activity-based models may even be lower than the traditional matrix-based approaches. This is illustrated empirically in the present paper by tests on the network from the Copenhagen OTM model. In addition it is shown that the equilibrium scheme of the trip-based approach converge faster than the matrix-based, whereby an additional benefit is a need for fewer iterations in the solution algorithm. Due to the many potential benefits of using a trip-based assignment model in terms of more refined casual relationships and consistency between the activities based model and the assignment, trip-based assignment seems to be a promising way forward. For the covering abstract see ITRD E137145.]]></description>
      <pubDate>Tue, 27 May 2008 09:26:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/859848</guid>
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    <item>
      <title>Some reflections on the transition to activity-based models in the U.S.</title>
      <link>https://trid.trb.org/View/859847</link>
      <description><![CDATA[It has now been nearly ten years since the first in a family of activity-based disaggregate microsimulation models of travel demand was applied in the US. Since that time, models in this same family have been applied in the cities of Portland, New York, San Francisco, Columbus, and Sacramento, and models are now under development for Denver, Oakland, Atlanta, Dallas,Lake Tahoe and other city and state government agencies. Although each ofthese model systems has its own distinguishing features, their similarities outweigh their differences, especially when contrasted to the traditional 4-step modelling approach. Now that there is evidence and experience from the application of a number of such models in the US, it is useful to consider whether or not the models appear to be living up to their promise.In cases where they are, examples are provided of what has been done withthe models that could not have been done with more conventional models. The first successful examples of activity-based model applications include various environmental impact studies, road-pricing projects and policies, large-scale rail / LRT/ BRT transit projects, and others. In cases where the models are less successful, the extent to which this is due to the models themselves or the way that they have been implemented and used is discussed. For the covering abstract see ITRD E137145.]]></description>
      <pubDate>Tue, 27 May 2008 09:25:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/859847</guid>
    </item>
    <item>
      <title>Reshaping freight demand modelling - a modelling framework for freight transport policy &amp; the environment</title>
      <link>https://trid.trb.org/View/855696</link>
      <description><![CDATA[The performance of current models with respect to forecasting freight transport demand is reviewed. The original motivation was to ask how freight modelling deals with discrepancies between observed model outcomes as model assumptions and forecasting results. In this context a lot of energy seems to be invested into the calibration process. The conventional approach for improving models is updating prior estimates through new information, thus an update in the level of the same kind of information. In the centre of the discussion the author places the idea of including into the modelling process an expression for an a priori unknown kind of information. The knowledge about both, the information of a new level and of a new kind, is acquired through the modelling process and then used in the calibration process. Consequently, the definition of the model assumptions must not only include a specification of everything that is true for the model (necessary assumptions) but also an exclusion of everything that is untrue (sufficient assumption). In current freight modelling scope for improvement has been identified in the area of strengthening the link to policy analysis. Freight modelling as a decision-making tool is lacking mechanisms to monitor the effect of policy measures. So far, the possibility of using freight demand models for policy simulation has not been sufficiently exploited. This is especially true for environmental targets such as stated in the Kyoto Protocol which hardly find any recognition in national freight models. In contrast to previous modelling approaches the proposed model includes a feedback mechanism linking emission estimates which are derived from freight transport forecasts back to transport policy design. The model consists of three modules, which are run under various policy scenarios, a freight demand module (LEFT), a supply chain design module (CAST) and an emissions module: The LEeds Freight Transport Model (LEFT) uses logit models to provide estimates of the effect of macroeconomically neutral scenarios on modal split (road, trainload and wagonload), average length of haul and total market size. The LEFT model is complemented with the strategic network optimization model CAST which is applied by shippers in the private sector for strategic design of their supply chains. In the context of this research CAST is used to model a national distribution network for the UK based on one-year data. The first two modules are used to deliver estimates on freight traffic activity on the basis of which emissions from a set of six air pollutants and greenhouse gases are calculated for the base year.In a next step, the estimated emissions are compared to the environmental target set by the government. Hence, the first iteration of the model attempts to predict the present. This means that the observed data and the model results refer to the same time span. The gap between the observed model outcomes in terms of actual emissions from freight transport can be closed by applying an appropriate set of transport policy measures, such as fuel tax. The objective of the first iteration is to determine the level of these measures. The obtained information is then used to update the original model assumptions. In the second iteration the model is then run under the new assumptions. In summary, the paper would like to contribute to a generic discussion on testing assumptions in freight demand modelling and increasing the accuracy of model forecasts. The underlying question concerns the gap between model observations and the model results. To reconcile the discrepancies a modelling framework is suggested which contains a feedback mechanism for updating information which may include information of a new kind and level. The example of using freight demand modelling for transport policy and the environment gives a flavour of a possible application in freight transport practice. For the covering abstract see ITRD E137145.]]></description>
      <pubDate>Fri, 25 Apr 2008 09:33:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/855696</guid>
    </item>
    <item>
      <title>Urban rail investments and property value gains in Athens: a case for alternative funding sources</title>
      <link>https://trid.trb.org/View/855621</link>
      <description><![CDATA[In many local contexts there exists evidence that urban rail investments induce around stations distinct property value gains. The main aim of the paper is to investigate the existence and magnitude of such premiums in the case of the new Athens LRT system, operating since the 2004 Summer Olympics and covering the southern suburbs of the agglomeration. The focus is on the city line section connecting the coast with the city centre. The market segmentation refers to residential as well as commercial properties. The comparison pertains to the 1.5-year periods before and after the LRT opening. The pooled data comprise 719 real asked prices for sale of properties close to LRT stops. Note that for tax evasion reasons, the nominal contractual prices seriously underestimate the market prices achieved by successful transactions. Offers are adjusted to consider the mean 2003-to-2005 property price changes in the southern suburbs due to factors other than rail accessibility. Note that in Athens, owners dominate the occupation of residential properties to 79% and of commercial ones to 53%. Several specifications of a price gradient have been tested as functions of the proximity to the nearest LRT stop. The chosen decay function predicts for residential properties an 8% premium within 250m from a LRT stop and a 2% premium within the range of 250 to 500m. Commercial properties display a 13% premium and a 1% discount respectively. Aggregated property value gains have been compared with model-estimated travel time savings from/to the 250m zone, the latter capitalised with the Value-of-Time figures of the multi-modal Metro Development Study conducted by ATTIKO METRO. The resulting positive difference may be ascribed to wider benefits beyond the direct accessibility savings.The paper examines further new ways of funding an LRT extension to Piraeus and the western suburbs through the conversion of property value gains into additional revenue generating opportunities. Revenue mechanisms based on land value gains are investigated in depth. Value recapture taxes applied on beneficiaries of public investments in urban rail infrastructure internalize some of the external benefits to private parties. A fair surplus portion corresponding to the unique contribution of the rail investment on the property value is suggested, given a mix of tax instruments. The allocation problem of an efficient taxation of relevant stakeholders is introduced. The instruments considered refer to (a) location benefit taxes paid on a recurring basis by property owners within 250m of LRT stops. It is calculated as a percentage increase on property ownership tax and is justifiable in terms of improved accessibility to employment or shopping opportunities, (b) business taxes paid on a recurring basis by larger commercial occupiers of properties within 250 m of LRT stops. It is calculated as an increment on business income tax and is defendable in view of an improved accessibility for employees, customers and visitors, (c) planning gains as one-off charge paid by property owners or developers in case of a hand-over or of granting planning permissions around LRT stops. A scaled fee is set in relation to the value of the transaction or of the project to be developed. The methodology and the results are considered to be of wider interest for planning agencies, transit authorities and policy makers. For the covering abstract see ITRD E137145.]]></description>
      <pubDate>Fri, 25 Apr 2008 09:23:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/855621</guid>
    </item>
    <item>
      <title>The OTM model and its application at the Metro City Ring project in Copenhagen</title>
      <link>https://trid.trb.org/View/855620</link>
      <description><![CDATA[The Metro City Ring project is the 4th phase of the expanding metro network in the Danish capital, and is expected to become operational in 2015. The metros phase 1 was opened in 2002, phase 2 in 2003, and the 3rd phase will be opened in autumn 2007. The operational traffic model for the capital, the OTM model, was updated over the last two years specifically for the purpose of the Metro City Ring project. The efforts were concentrated on the data part of the model where new 2004 base matrices were built. In addition, the demand model components have been re-estimated, combing values-of-time (VOT) derived from a large Stated Preference survey (based on the newly completed data for the Danish national VOT project) with Revealed Preference data collected across the Greater Copenhagen Area. The aim of the paper is twofold. Firstly, the structure of the new OTM demand model is depicted and secondly, the demand forecasts produced by the model for the Metro City Ring project are presented. The OTM model system predicts demand for transport across the Greater Copenhagen Area. Forecasts of demand are made separately for seven passenger purposes. In application, the predictions from the home-based business and non-home-based business models are aggregated into a single business purpose prior to assignment. The OTM consists of separate model components by purpose for travel frequency (generation) at the all-day level, and models of simultaneous mode and destination choice. The modes in the model are car driver, car passenger, public transport, bike and walk. Three tree structures were tested to determine the relative sensitivities of the mode and destination choice decisions: mode and destination choice in parallel, mode choice under destination choice and destination choice under mode choice. A key feature of the model is that the VOT are income dependent, which allows the demand models in the model system to reflect variations in cost sensitivity with income. The model base travel matrices reflect conditions on an average weekday in 2004. Once the model has been estimated synthetic 2004 travel matrices are produced. A pivoting procedure is used then to combine information from the base matrices with the changes in synthetic demand between the base and forecast years. Prior to assignment, the model predictions are split between seven model time-periods distinguished in the assignment by using fixed factors. When completed, the Metro City Ring alignment will be 15 km long including 17 underground stations. The total travel time, including time spent at stations, will be 23 min. Approximately 180.000 people and 190.000 working/education places will be on a walk distance to one of the Metro City Ring stations. In 2015, when it is expected that the new metro infrastructure is finished, some 85% of all dwellings and working/education places in the city will be within a 600 m radius of the metro and S-train network. In the peak periods, the Metro City Ring is forecast to carry 5.500 passengers per hour per direction. With the 100 s headway in the peak periods, the maximum capacity is 10.800 passengers per hour per direction, i.e. approximately the double of what is needed. Model forecasts with the new OTM will be carried out during spring 2007 where different alignment possibilities will be tested. Prior to model forecasts the model was validated by comparing the calculated and observed traffic flows in the base 2004 year. For the covering abstract see ITRD E137145. For the covering abstract see ITRD E137145.]]></description>
      <pubDate>Fri, 25 Apr 2008 09:23:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/855620</guid>
    </item>
    <item>
      <title>Building a rich activities-travel database from an OD survey</title>
      <link>https://trid.trb.org/View/855619</link>
      <description><![CDATA[Although an origin destination (OD) survey is devoted to describe in detail the travel pattern in a particular period, the information collected allows recovering, with some level of aggregation, a description of time use of the individuals observed. This allows the possibility to calibrate the time use mode choice model system proposed by Jara-Diaz and Guerra (2003) with a very rich and trustable database. This possibility is explored for the Santiago 2001 OD survey (Ortzar et al, 2003) that has more than 12,000 households sampled randomly from the population of Santiago, each observed during a whole day. As a first stage of this process, we analyze the available information and identify the possible ways to build adequate descriptions of the individuals time assignment to different activities. The sociodemographic characteristics of the sample, which could be used as segmentation variables and to link observations, was also observed. The objective of this work is to obtain from the OD survey, a database similar to one obtained specifically with the purpose of calibrating the time use mode choice model system, which is much smaller in size. The information required to calibrate the time use mode choice model system, and how it can be obtained from the Santiago 2001 OD survey is identified. From this information, we obtain the time allocation to different activities of a representative sample of the inhabitants of Santiago (the OD sample), and analyze the individuals characteristics that influence these time allocations. There are two basic ways to describe the time assignment of a group of individuals: trough the average time assignment and through the activity pattern, that represents the proportion of individuals who are conducting each particular activity at any instant through a period of time, for example a day. Because the OD survey is a travel survey and not a time use survey, the activities can only be obtained through trip purposes, and the degree of aggregation is constrained to the trip purposes included in the OD survey. The detail of what happens inside each of these aggregate activities is not known. The activities that can be deduced from the Santiago OD survey are: stay at home, work (out of home), study (out of home), recreation (out of home), shopping and errands, travel, other activity out of home. As each individual was observed only during one day, the activity patterns of the different days of the week come from different individuals. Although comparisons among days can be made, it would be interesting to build weekly observations through linking observations of very similar individual observed in different days of the week. The analysis is centred on the possibility of aggregating information and generating databases rich in variance, that allow to calibrate the time use mode choice model system, already applied to smaller databases. If we prove it feasible to obtain all the information required from such a large and rich database, we will then count with a very powerful approach to the better understanding of individuals behaviour. For the covering abstract see ITRD E137145.]]></description>
      <pubDate>Fri, 25 Apr 2008 09:23:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/855619</guid>
    </item>
    <item>
      <title>Optimality and efficiency requirements for the design of stated choice experiments</title>
      <link>https://trid.trb.org/View/855618</link>
      <description><![CDATA[To assess the value of aspects of transport alternatives researchers often apply survey techniques that allow them to explore public preferences for hypothetical scenarios. A widely-used standard survey technique for this purpose has been the contingent valuation method. In the last twenty years, stated preferences (SP) approaches have been used in several contexts of interest, including transport analysis. SP is a technique that can be used to assess values for attributes of market or non-market goods based on survey respondents' willingness to trade-off different bundles of these attributes. Most recently, the Stated Choice approach has been the most widely used of the Stated Preference methods, as it is believed to approximate most closely to actual consumer behaviour. Because of cost considerations, sample sizes are often limited to the smallest that researchers consider necessary. By employing optimal survey design techniques, practitioners can increase the informational content of each observation, producing the equivalent effect of a larger sample size. In this context, the main goal of this paper is to describe a procedure to construct optimal SP designs that, given a fixed number of observations, will provide the most information possible about parameter estimators of interest, such as mean or median willingness to pay. In so doing, the paper aims to extend the existing literature on the optimal design of surveys to apply discrete choice modelling (DCM) in three ways: first, by arguing the limited applicability of the concepts of traditional conjoint analysis to build choice sets to apply DCM, second, by analysing the different and sometimes competing ways to define the optimality required, and third, by discussing the influence on design optimality of the ultimately more important issues of reliability and credibility of the responses. The paper also addresses with the dissimilar criteria that have been used in the literature to measure the covariance matrices of the parameters to be estimated. The different ways to calculate these matrices and the assumptions on which their use is based are assessed, aiming to give practical advice to choice designers. The type of DCM that is going to be applied over the responses collected also affects the process to design such survey. The issue of orthogonality in SP designs is addressed; this is a property often sought by designers, since when it applies the parameter estimates are independent in their explanation of the observed responses, which does not necessarily imply that these estimates will be significant. This issue is particularly relevant for larger and more diverse designs. In conclusion, the paper offers a number of insights and results that will be of assistance to the designers of SP surveys in their attempts to maximise the effectiveness of survey budgets. For the covering abstract see ITRD E137145.]]></description>
      <pubDate>Fri, 25 Apr 2008 09:22:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/855618</guid>
    </item>
    <item>
      <title>Modelling indifference in binary SP choice experiments</title>
      <link>https://trid.trb.org/View/855617</link>
      <description><![CDATA[Choice behaviour is affected by complex factors; in addition, when facing new situations people might undergo a process of experimentation and learning, through trial and error. These represent a challenge to improve realism in modelling work. Furthermore, the choice process may present restrictions on the perception and evaluation of attributes that can vary within the population according to certain characteristics that are referred to as thresholds. These thresholds of perception can be seen as "just noticeable differences". In this sense, perceptible changes would be values above a threshold whereas those below it would not cause a reaction in the individual because utilities do not change. It may also happen that utilities are so similar that are perceived as equal by the individual. The use of binary Stated Preference (SP) surveys in which the individual can choose between only two alternatives is very frequent in applied work. However a good design requires that utilities are balanced, and this may imply cases where utilities are so close to be undistinguishable for the respondent; for this reason, it may be important to incorporate an "indifference option". A discrete choice model to adequately treat this case is developed. To model the inclusion of an indifference option thresholds are considered that are dynamic and depend on the experiences and restrictions of the respondents. Thus, it is possible to postulate that these thresholds vary in the population, according with the concept of psychological threshold in the theory of consumer choice. A discrete choice model is proposed that describes the behaviour of individuals when they confront thresholds of indifference which let them obtain similar utilities from specific situations in a SP experiment. As an important contribution, our model introduces the indifference option so that the individual is not forced to choose one alternative at first view. It is postulated that if thresholds exist they could be stochastic, random, differ among population and even be a function of socio-economic characteristics and choice conditions. This formulation allows estimation of the parameters of the threshold probability distribution starting from information about choices. The model was applied to synthetic data and to real data coming from a SP survey with rating data and found that if there is evidence about the existence of perception thresholds in the population, the use of models without this capability should lead to errors in prediction and in estimation, although this only occurs when the effect of the indifference threshold in the utility function is strong. For the covering abstract see ITRD E137145.]]></description>
      <pubDate>Fri, 25 Apr 2008 09:22:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/855617</guid>
    </item>
    <item>
      <title>Identifying differences in preferences due to dimensionality in stated choice experiments: a cross cultural analysis</title>
      <link>https://trid.trb.org/View/855616</link>
      <description><![CDATA[The need for respondents to repeatedly process information on the attributes and attribute levels of alternatives within stated choice (SC) surveys has resulted in the continual calling into question of the ability of respondents to accurately undertake such tasks. Of concern is the cognitive load under which respondents are placed in answering SC choice surveys as well as the possibility of fatigue effects rendered through repeated questioning. Research efforts have tended to focus upon the impact various design characteristics have upon respondents ability to respond to choice tasks. Specific issues examining the impact upon behavioural responses have included the number of alternatives within the task, the number of attributes, the number of attributes and alternatives, the impact of attribute level range upon and the number of choice profiles shown to respondents. Of particular concern is fact that research examining the impact of design dimensionality upon SC studies has often yielded contradictory evidence. For example, early research found that the first few choice situations of SC tasks are often used by respondents to adapt to the task and develop a decision strategy. A number of researchers have examined the impact that the number of profiles has on the behavioural responses of respondents completing SC tasks. In each instance, these researchers found no evidence that the number of choice tasks has more than a marginal impact upon the behavioural responses of respondents. However the issue of the number of choice profiles respondents are capable of handling remains a contentious issue within the literature and there remains a perception that respondents can handle no more than small number of choice tasks (usually anywhere between three and 16). One problem in forming a clear understanding as to the exact influence different design dimensions play in obtaining SC results is that different researchers often use different experiments, conducted at different times, in different cultural settings. Interestingly, Caussade et al. (2005) collected data in Chile using the same survey instrument developed by Hensher (2004) in Australia. A third survey using the same survey instrument was conducted in Taiwan in 2006. These three data sets offer, if combined, a unique opportunity to examine whether design dimensionality has a similar impact upon results obtained from SC studies in three very different cultures.This paper examines combing the three data sets and testing whether the influences of design dimensionality are culturally biased, or constant across the two cultures. The research starts by examining simple questions such as do respondents from both countries devout the same amount of time to SC questions (data that was passively collected), before moving to a more advanced and scientifically rigorous examination of differences in the population moments of random parameter distributions as well as influences on the error components of models. For the covering abstract see ITRD E137145.]]></description>
      <pubDate>Fri, 25 Apr 2008 09:22:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/855616</guid>
    </item>
    <item>
      <title>The impact of information and communication technologies on female activities: the case of Greece</title>
      <link>https://trid.trb.org/View/855615</link>
      <description><![CDATA[The use of modern technology has assisted in the development and adaptation of new habits by individuals in their daily activities. Concepts like teleworking, tele-education, tele-shopping, etc. may lead to a reduction of mobility needs allowing people to organize and reprogram their activities the best way possible. The aim of this paper is to examine the level of usage of Information and Communication Technologies (ICTs) by women and identify their effect on the programming of their daily activities (such as education, leisure, transactions, entertainment) along with their career development. Emphasis is given on the comparison between women that live in rural and less favoured areas in order to examine the differences in perceptions and attitudes towards new technologies. A personalized questionnaire designed to capture womens decision making behaviour was developed. The data collection methodology involves the collection of 600 questionnaires collected via personal interviews and Information Acceleration internet surveys. The sample has been selected from a number of different and diversified Greek provinces in order to assure representativeness of the population as possible. Preliminary analysis of the data shows that the Greek women studied use modern technologies in their daily activities in a relatively low rate, when compared with other EU countries and the USA. In both rural and less favoured areas they prefer to use the traditional means of transport for their usual activities (work, children care, shopping, etc.). In suburban areas and islands this phenomenon is more evident due to the small familiarity with the use of computers. A significant result was the positive correlation between the level of salary, education and the use of modern technologies for activities such as e-banking and e-shopping. Another result is that companies seem to prefer the physical presence of women at the working environment since promotion of teleworking is still limited. Finally, the scenario analysis revealed a preference women familiar with ICT to relocate to the suburbs and islands and entrepreneurs to less favoured areas when government subsidies are generous and the cost of communications and travel are at reasonably low prices. Further research involves the estimation of mixed logit models using the Stated Preferences data, to model womens' choices in terms of using ICTs and conduct tele-activities. These models will demonstrate complementarity and substitution effects between activities conducted via e-mode versus the traditional mode. For the covering abstract see ITRD E137145.]]></description>
      <pubDate>Fri, 25 Apr 2008 09:22:23 GMT</pubDate>
      <guid>https://trid.trb.org/View/855615</guid>
    </item>
    <item>
      <title>Mass deployment of bus priority using real-time passenger information systems in London</title>
      <link>https://trid.trb.org/View/855614</link>
      <description><![CDATA[In 2005 Transport for London purchased one of the worlds largest real-time passenger information and fleet management systems in a project valued at 117M with the objectives of equipping 8000 vehicles with GPS tracking and installing500 passenger information signs. The option to expand the system to deploy priority at traffic signals for buses was made in April 2006 which requires up to 3200 sets of signals to be upgraded. With such a large scale deployment a number of useful tools and methods have been developed to minimise waste and improve efficiency. In view of the increasing competition for road space, an important tool for improving bus services is bus priority at traffic signals. This can increase buses share of the time available at signalled junctions, reduce delays to buses at junctions and potentially provide greater regularity in bus schedules. Bus priority in London was developed by the use of selective vehicle detection to give buses priority extensions and recalls at traffic signals. Previous systems have used transponders fitted to the buses linked to antennas buried in the carriageway (bus loops) and roadside beacons communicating with on-bus transponders via a short microwave link. Currently, 45% of the 3200 signalled junctions are fitted with one or other of these types of equipment. Bus priority at signals has contributed to the 38% increase in bus patronage since 1999. A description of the IBUS system is provided. It is fitted to 8000 buses (scope for 16000); and all 3200 traffic signals are to be fitted. Virtual detectors are used, avoiding on-street hardware. RTIG standard radio link from buses to signals adapted to allow ACK from signals to bus. Provision for messages from signals to buses is a future option. A bus processor unit provides an interface to signals. The network of bus processors is connected to a bus priority instation. There are extensive data collection and monitoring facilities in the iBUS central system allowing greatly improved system management for bus priority. The system supports a short range radio link for message transmission to traffic signals, giving up to 4 notifications for an approaching bus. The location of the virtual bus detector in each approach to the junction is dependent mainly on the extension requirements. Bus priority is currently awarded through green extensions and green recalls. It has been shown that green extensions are most sensitive to detector siting and that optimal siting for green extensions is also appropriate for green recalls. Optimum detector distances have been calculated for different bus speeds on different categories of approach. A different method is needed where there is a bus stop close to the signals and iBUS contains special procedures for triggering the priority request at bus stops in order to obtain the maximum benefit to the buses. The benefits from bus priority at signals are well understood and documented in London as a result of previous experience over a period of 20 years. The analysis used in the development of iBUS indicated that total costs over the 15 year expected lifetime of the system, including capital and operational costs would be 39M and that benefits would be 147M, giving a Net Financial Effect of 108M. The magnitude and timescale of the roll-out (800 junctions/year over four years) plus the need to work in harmony with existing complex technical and organisational structures calls for a high degree of organisation. For the covering abstract see ITRD E137145.]]></description>
      <pubDate>Fri, 25 Apr 2008 09:22:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/855614</guid>
    </item>
    <item>
      <title>Traffic management concept for new inner semi-circular ring road in Belgrade</title>
      <link>https://trid.trb.org/View/855613</link>
      <description><![CDATA[Belgrade is the capital of Serbia, a city with 1.5 million inhabitants, which together with the reference urban hinterland has almost 2 million inhabitants. Components of radial character dominate functionally in the geometrically irregular configuration of the core street network, and previous monocentric urban structure contributed to formation of strong tradition of attractiveness of the city centre. Capacitative limitation of the traffic network of the old city core, insufficient parking capacity and conflict with transit movements represent the key components of the traffic problem of the city. It is expected that this problem will be considerably alleviated with radical improvement of public mass transit (by construction of Light Rail Transit System) and construction of the Inner Arterial Semi-Circular Road. The Inner Arterial Semi-circular Road (IASR) is the future arterial street which, for the Belgrade street network, should provide capacitative and dynamic potential required for anticipated traffic demand in the decades to come. It is planned as a fast urban road stretching along the fringe of a broader city centre, which frees the central city area from excess transit flows and, for its origin and destination movements, provides effective connection with urban hinterland and city access routes. The first phase of IASR construction consists of 2 km of relatively lighter route through regular and systematically designed street network in the new part of the city, from 1.5 km long bridge over the Sava River and from its connection with strong radial corridor linking two approach routes and large urban hinterland with the city centre. In order that IASR retains attributes and character of a city artery it was necessary to provide appropriate approach control related to adjacent street network. This was initially determined by adequate alignment and selective physical connection with the elements of surrounding street network. The most delicate and loaded link was the contact with the existing radial city arterial street on the other bank of the Sava River. Two alternative solutions were evaluated in detail both from the aspect of costs of their total physical implementation and from the aspect of traffic process efficiency such solutions should serve. One solution is based on the classical concept of completely grade-separated intersection (similar to grade-separated intersections on motorways), and the other solution is based on the concept of intersection containing both grade-separation and accesses to adjacent traffic light controlled network. Reality and functionality of both solutions have been checked and functionally evaluated for the forecasted traffic loads by microscopic simulation. The second component of approach control - which is more important in dynamic sense- is applied ITS traffic management system along IASR, combined with management solution for observed intersections. Proposed was a rational, functional and multistage management solution, which implies compatibility with the adjacent management systems on the network, open architecture and concept suitable for technological upgrading and development of hardware and software components. At the same time, the proposed solution is integrated into future traffic management system on the Belgrade city street network, the design and implementation of which is in progress. The paper will present all relevant numerical and other indicators which illustrate functionality and quality of the observed alternatives and explain the suggested decision. For the covering abstract see ITRD E137145.]]></description>
      <pubDate>Fri, 25 Apr 2008 09:22:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/855613</guid>
    </item>
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