en-us Tue, 5 Jun 2012 00:25:27 UTC Inmagic DB/Text WebPublisher http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR291E Mon, 14 May 2012 14:00:00 UTCThis paper presents a model of same-day mode choice at the household level for developing countries. A rule-based algorithm combining classical random utility maximization theory within a microsimulation framework is used. Modeling of private vehicle usage (including vehicle allocation and sharing use in household) is an essential component of this model because vehicle deficiency is common in developing countries. This model consists of four steps: (a) the allocation of private vehicles (car, motorcycle, and bicycle) in a household, (b) the mode choice of private vehicle users specified in the first step, (c) vehicle sharing in a household, and (d) the mode choice of individuals who do not use private vehicles. The adaptability of the model was improved by simulations on car, motorcycle, and bicycle usage. Discrepancies in the mode choice behavior of household members with and without the use of private vehicles are captured in this paper through different modeling methods. The rule-based algorithm, binary logit model, multinomial logit model, and mixed logit model were applied together in this four-step model. Travel diary survey data from 2007 from Bengbu, China, were used as an example for the validation test of this model. The results demonstrate that this model can accurately predict the mode choice of all household members in an internally self-consistent and theoretically credible manner for a midsize city in China. The proposed model is highly conducive to travel demand forecasting and transportation policy making. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR235E Mon, 14 May 2012 14:00:00 UTCNonresponse results in a reduced sample size, but a more important concern of researchers is the possible impact of nonresponse bias. Bias is introduced when those who do not respond to the survey are systematically different from those who do respond on key variables of interest. The response mechanism is defined as "ignorable" when it can be modeled with the available characteristics (e.g., from the sample base). For example, if the nonresponse mechanism depends on the level of income, the respondent sample must be reweighted according to the distribution of income to correct the nonresponse errors. For the French National Travel Survey 2007-2008, the sample was drawn directly from the census and the list of new residences built since then. Therefore, there is considerable information about respondents and nonrespondents. The response mechanism is modeled first, and then calibration strategies are discussed. The nonresponse biases are quantified by using auxiliary information in different calibration exercises. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR237E Mon, 14 May 2012 14:00:00 UTCThe paper describes recent experience with the application of an innovative Global Positioning System (GPS)-assisted prompted recall (PR) method for a large-scale household travel survey (HTS) in Jerusalem, Israel. The survey was designed to support development of an advanced activity-based model (ABM). The requirements for an HTS to support an advanced ABM are discussed, and the corresponding decisions for survey methods are substantiated. Development of an advanced ABM requires individual records for the entire daily pattern without gaps, missing trips, overlaps, or other data inconsistencies found in a conventional HTS. A consistent record of joint activities and trips of multiple household members is essential. In addition, high levels of spatial and temporal resolution are required. The GPS-assisted PR survey has been identified as the most promising methodology for meeting these requirements. The experience of the first phase of the Jerusalem HTS in 2010 proved the feasibility of the GPS-PR method for all population sectors including specific Orthodox Jewish and Arab populations, which typically featured large household sizes. Various structural comparisons of trip and tour rates obtained during the first phase of the Jerusalem GPS-assisted HTS (3,000 households) with the non-GPS surveys previously implemented in Jerusalem and several metropolitan regions in the United States as well as comparisons between the GPS and non-GPS subsamples within the Jerusalem HTS were made. The results confirmed the ability of the GPS-PR approach to create full and consistent daily records of individual activity travel patterns and practically eliminate the underreporting issues that have plagued HTS. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR238E Mon, 14 May 2012 14:00:00 UTCThe Maricopa Association of Governments (MAG) is the designated metropolitan planning organization for the Phoenix, Arizona, metropolitan area. In collaboration with local transit agencies and local jurisdictions, MAG developed a successful proposal to compete for FTA Alternatives Analysis Discretionary Program Section 5339 funds. The proposal included development of the special events model and special events data collection. The importance of this task was highlighted by the success of the introduction of light rail transit in the region. The need for better understanding and forecasting of transit markets required in-depth study and modeling of planned special events in the region. Special events patrons constituted a significant portion of light rail ridership and overall regional travel demand. This paper focuses on the first results of this effort, including the completed special events data collection and some preliminary data analysis results. The special events surveys used advanced data collection techniques that allowed better data expansion and processing and ultimately will facilitate development of advanced special events travel demand forecasting models. The paper discusses survey design, survey instruments, counting and interviewing processes, organizational issues, and data expansion procedures. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR239E Mon, 14 May 2012 14:00:00 UTCMany studies have compared Global Positioning System (GPS) and diary records to estimate the amount of misreporting of travel that occurs in self-report diaries. This paper examines the comparison of GPS and diary records in detail to further the understanding of what leads to misreporting in diary surveys. The research is based on a recent comparative survey undertaken in the area of Melbourne, Victoria, Australia. The survey is analyzed in depth, and diary records are compared in detail with GPS records to check whether the two groups of data match. Departure and arrival times, trip lengths, and trip times are compared. Reasons for mismatches are suggested. The paper proposes some values as standards for similar analyses in the future. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR242E Mon, 14 May 2012 14:00:00 UTCThis paper presents findings from a small-sample qualitative study on people's activity travel behavior in the presence or absence of carsharing. A carsharing service provides its subscribers with short-term access to a fleet of shared cars. In previous research, subscribers have reported distinctive travel patterns, such as more car usage by subscribers than by non-car owners but less than by car owners. Reflexive techniques were used in which interviewees adapted a week of their recent activity travel behavior in response to stimuli. Findings from this study informed the design of a stated-choice survey that addressed three principal forms of complexity: (a) strategic-tactical choice situations, (b) situations in which respondents might select multiple interacting options in a single choice situation, and (c) situations in which sufficient knowledge of the individual survey respondent to tailor such a complex choice situation could not feasibly be gathered during a single interview. In the proposed design, the respondent indicates a strategic choice of which methods of travel to make available for use given a set of representative out-of-home activities. Accessibility to each activity by various means of travel is generated by using empirical distributions from Britain's National Travel Survey data sets to maximize plausibility of the information presented to respondents. An avatar (a virtual character for purposes of the survey) is constructed for each respondent on the basis of a small set of self-reported demographic characteristics. The use of multiday activity travel diaries would ideally involve multiple points of contact with each respondent at substantial cost. Therefore, an alternative method involving a single interview per respondent was sought. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR243E Mon, 14 May 2012 14:00:00 UTCOrigin-destination (O-D) flows at the bus passenger route level have traditionally been estimated from costly and labor-intensive onboard surveys. The availability of automatic passenger counter (APC) data on many bus transit systems offers the possibility of enhancing the quality of the onboard survey data at little marginal cost. This paper investigates the value of estimating route-level passenger O-D flows from APC data and onboard O-D survey data with a focus on the effect of onboard O-D survey sample size. An empirical study using field data collected on three bus routes investigates and quantifies the value of combining APC counts with onboard O-D survey data as a function of survey sample size. Encouraging estimation performance obtained in using APC data with no onboard O-D survey data, previously seen in a smaller study, is confirmed in this more extensive study. In addition, incorporating onboard O-D survey data with APC data produces O-D flow estimates that are better than those produced by using only the APC data, and increasing the sample size of the onboard O-D survey improves the quality of these estimates. However, the magnitude of the improvement depends on the O-D flow structure of the given bus route; increasing sample size results in less appreciable improvement for routes with more concentrated O-D flows than for routes with more evenly distributed O-D flows. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR256E Mon, 14 May 2012 14:00:00 UTCA key issue for both sustainable transport and public health is the viability of cycling as an alternative to the car, particularly for short trips. This study assessed the travel time implications of hypothetically substituting actual car trips with cycling. The car trips were captured over several weeks for 178 motorists in Sydney, Australia, through Global Positioning System technology. The cycling trips were generated with reverse geocoding processes in geographic information system software. This process took into account the impacts of terrain on cycling travel times. Both individual trips and trip chains were considered. Results suggested that for an inexperienced adult cyclist more than 90 per cent of car trips of up to 5 km (58 per cent of trips) could be cycled within 10 min of the time taken by car. As the level of cycling experience increased, the bikeable distance increased: the majority of commuter adults could cycle the median commuting distance in Sydney of 11 km with little additional travel time compared with a car. For trip chains, although the competitiveness of cycling decreased as more legs were included, the total distance of the chain emerged as a more crucial issue. Cycling was found to be as competitive for trip chains shorter than 10 km as for individual shorter trips. Finally, results showed that in the context of daily travel time budgets, approximately 20 per cent of people could switch totally from cars to bicycles without incurring more than a 20-min additional increase in travel time on average per day. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR257E Mon, 14 May 2012 14:00:00 UTCIn response to the environmental, economic, and social costs associated with overreliance on the automobile, planners and transportation professionals are promoting sustainable alternatives such as walking, cycling, and public transit, either as single modes or in combination. It has been argued that the marriage between cycling and transit presents opportunities for synergy by enlarging catchment areas of transit stations while drawing in new users to both of these green modes. However, because of the marginality of combining cycling and transit in North America, there is a shortage of reliable empirical studies in this area. The present study addressed this gap through an analysis of travel behavior and preferences related to cycle-transit (C-T) integration. An online survey was conducted in the region of Montreal, Canada, during the summer of 2010. The questionnaire included a section on Montreal's public bicycle sharing system, Bixi (bicycle taxi), and its potential for integration with transit. Three current or potential C-T user groups were identified through a factor-cluster analysis: current parking bike-and-riders, Bixi users, and car drivers. Bringing a bicycle on transit was the preferred form of integration; however, scenarios involving bicycle parking (or using a public bicycle) were likely to be used more regularly. To accommodate the greatest number of bicycle-transit trips, measures that facilitated parking at transit stops and those that enabled the bringing of bicycles on board transit vehicles were recommended in tandem. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR258E Mon, 14 May 2012 14:00:00 UTCCycle centers have emerged as a new travel demand management (TDM) intervention in U.S. and Australian cities in recent years. These large end-of-trip facilities for cyclists offer bicycle storage, changing rooms, lockers, showers, bicycle repair, and other amenities, on a user-pays basis. The effectiveness of these centers as a TDM measure is not known. Australia's first cycle center opened at King George Square in Brisbane's central business district in 2008. Operated by the private sector and marketed as cycle2city, the center provided storage for 420 bicycles. An evaluation framework was derived directly from the stated aims and objectives of the funders and manager-operators of the center. In April 2009, a questionnaire was sent to cycle2city members. The questionnaire was supplemented by interviews with funding agencies, the center's operators, and members. Route maps collected information on trip distances and the routes members chose to ride. The results showed who had been using the center, the travel modes they had been attracted from, and the transport benefits. Most users were men in white-collar jobs. The majority of members had commenced commuter cycling on joining cycle2city, at which time they switched from transit and the private car. Congestion-reduction benefits were small. The facility was not generating enough revenues to meet operating costs some 2 years after opening. The findings had direct implications for transport policy regarding the role and potential use of cycle centers for TDM in cities. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR261E Mon, 14 May 2012 14:00:00 UTCCharacteristics of the road infrastructure affect both the popularity of bicycling and its safety, but comparisons of the safety performance of infrastructure may be confounded by differences in the profiles of cyclists who use them. Data from a survey of 2,532 adult bicycle riders in Queensland, Australia, demonstrated that many riders rode reluctantly in particular locations and that preference for riding location was influenced by degree of experience and riding purpose. Most riders rode most often and furthest per week on urban roads, but approximately one-third of all riders (and more new riders) rode there reluctantly. Almost two-thirds of riders rode on bicycle paths, most by choice, not reluctantly. New riders rode proportionally more on bicycle paths, but continuing riders rode further in absolute terms. Utilitarian riders were more likely to ride on bicycle paths than social and fitness riders and almost all of this riding was by choice. Fitness riders were more reluctant in their use of bicycle paths, but still most of their use was by choice. One-third of the respondents reported riding on the sidewalk (legal in Queensland), with approximately two-thirds doing so reluctantly. The frequency and distance ridden on the sidewalk was less than for urban roads and bicycle paths. Sidewalks and bicycle paths were important facilities for both inexperienced and experienced riders and for utilitarian riding, especially when urban roads were considered a poor choice for cycling. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR264E Mon, 14 May 2012 14:00:00 UTCThis study investigated the relationship between weather conditions and cycling ridership, as well as the hourly, daily, monthly, and yearly trends for use of urban bicycle facilities. A unique data set of cyclist ridership, collected at five automatic counting stations on primarily utilitarian bike facilities in the city of Montreal, Canada, was used. Absolute and relative ridership models were used to analyze the direct and lagging effects of weather variables and extreme weather conditions on hourly cyclist volumes. Precipitation, temperature, and humidity had significant effects on bicycle ridership. After other factors were controlled for, when the temperature doubled, a 43 to 50 per cent increase in ridership could be expected; however, the temperature had a negative effect when it was higher than 28 degrees C and humidity was greater than 60 per cent. The results also showed that bicycle volumes in a given hour were significantly affected not only by the presence of rain in the same hour but also by the presence of rain in the previous 3 h or in the morning only. Daily bicycle volumes were 65 to 89 per cent lower on weekend days than on Monday, the weekday with lowest ridership. This finding confirmed that the analyzed facilities were primarily utilitarian. Further, bicycle volumes peaked in the summer months, with an additional ridership of 32 to 39 per cent with respect to April. Finally, bicycle volumes increased by approximately 20 to 27 per cent in 2009 and 35 to 40 per cent in 2010 with respect to 2008 in the cycling facilities under analysis. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR265E Mon, 14 May 2012 14:00:00 UTCThis study explored a methodology for assessing a neighborhood's bicycle accessibility or "bikeability" on the basis of its mix of infrastructure and destinations, essentially the 20-min neighborhood for bicycles. Prior approaches to assessing bikeability were examined. A new method to measure bikeability that incorporates extensive bicycle infrastructure and land use destination location data is described. The assessment method compared neighborhoods in Portland, Oregon, that had significant differences in bicycle usage. On the basis of the new method, the findings confirmed that, taking into account route infrastructure and destination accessibility, East Portland locations were considerably less bikeable than Inner Portland locations. The assessment method was then rerun to incorporate potential investment and development scenarios to understand how they might affect neighborhood bikeability. The methodology provided steps toward making an objective bikeability assessment—asking if a place could be considered a 20-min neighborhood by bike—and pushed the effort to integrate transportation infrastructure and land-use factors. In its application, the process could be used to explore where planned (or hypothetical) infrastructure or development could be most helpful and which neighborhoods might not receive much added value from the planned improvements. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR267E Mon, 14 May 2012 14:00:00 UTCShared lane markings (sharrows) convey the message that motorists and cyclists must share the travel way on which they are operating. The purpose of the markings is to create improved conditions for bicycling by clarifying where cyclists are expected to ride and reminding motorists to expect cyclists on the road. A before-after evaluation was conducted to compare how cyclists and motorists operated on a street with parallel parking in Cambridge, Massachusetts, with no markings versus with sharrows placed 10 ft (3.05 m) from the curb. This evaluation, which was part of a broader FHWA study on sharrows, was intended to help determine whether an alternative to the 11-ft (3.4-m) spacing recommended in the 2009 version of the Manual on Uniform Traffic Control Devices would be effective. Operational and safety measures for bicyclists and motorists were examined. Overall, safety effects appeared to be associated with the installation of the sharrows placed 10 ft (3.05 m) from the curb. Perhaps the most important effect was the 14-in. (36-cm) increase in spacing between motor vehicles in the travel lane and parked motor vehicles when no bicycles were present. This effect increased the operating space for bicyclists. Many variables related to the interaction of bicycles and motor vehicles also showed positive operational and safety effects. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR021E Mon, 14 May 2012 14:00:00 UTC http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR022E Mon, 14 May 2012 14:00:00 UTC http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR023E Mon, 14 May 2012 14:00:00 UTC http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR025E Mon, 14 May 2012 14:00:00 UTC http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR036E Mon, 14 May 2012 14:00:00 UTC http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR041E Mon, 14 May 2012 14:00:00 UTC http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR043E Mon, 14 May 2012 14:00:00 UTC http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR076E Mon, 14 May 2012 14:00:00 UTC505 vehicle owners responded to a structured questionnaire to examine the mechanisms that lead consumers to want larger vehicles and resist downsizing. An experimental within-subjects manipulation hypothetically replaced a driver’s current vehicle with a vehicle that was either higher or lower in design capability, and measured perceived lifestyle consequences. In baseline conditions drivers consistently regard their main vehicle as ideal for their lifestyle across all vehicle types, except in multiple-vehicle households where capability deficits of a main vehicle are offset by retaining an alternative vehicle. Participants considered the influence of a replacement vehicle on 12 trip types that require higher demands on vehicle capability but make minor contributions to annual vehicle travel, influencing only 2.5% of annual trips. Participants were found to adjust their perceived lifestyle expectations to match any increase in their vehicle resource by increasing the likelihood of undertaking rare trip events (such as going off-road). Conversely, participants were found to be loss-averse to a decrease in design capability, albeit for trips that they report they rarely undertake. These two key mechanisms operate together to promote an increase in average vehicle size and produce a resistance for consumers downsizing vehicles. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR077E Mon, 14 May 2012 14:00:00 UTCPark and Ride (P&R) schemes have many potential benefits, yet there is evidence that they can lead to an overall increase in private car use as a result of traffic redistribution, additional trip generation, and abstraction of users from the public transport system. This paper reports on research into the recently established Adelaide Entertainment Centre P&R facility situated on the fringe of Adelaide’s CBD. The research was conducted a few months after the opening of the P&R facility to capture the travel behaviour changes facilitated by the scheme. The results show little evidence of additional trip generation and a moderate level of car interception: 29.8% of users had previously driven into the CBD but now use a car-mass transit combination. What is disturbing though is the number of people who have shifted away from using public transport for their entire journey to using a car-mass transit combination: 82.3% of respondents who previously used mass transit for their entire journey now travel part of the way by car. The results of a single study need to be treated with caution; however, they do highlight the importance of carefully considering the location of P&R stations and the implications of the changes they enable. This research also highlights the need for more independent research into Australian P&R schemes in order to more clearly understand the specific dynamics of these facilities, and whether this compares with international findings. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR133E Mon, 14 May 2012 14:00:00 UTC http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR139E Mon, 14 May 2012 14:00:00 UTC http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR164E Mon, 14 May 2012 14:00:00 UTCThis study seeks to improve our understanding of the “transfer penalty” that is created in the minds of public-transport users for routes with interchanges. The results of the study are on the major interchange attributes which influences the intention of public transportation users to use routes which require making inter-mode and intra-mode transfers. To obtain a deeper understanding of the “transfer penalty” set on routes with interchanges, the Theory of Planned Behaviour was used to explore the role of perceived behavioural control in the traveller’s intention to use routes which involve making a transfer. A survey was undertaken in two of the major transport hubs in Auckland, New Zealand. The key findings indicate that the transfer penalty of a route has a strong relationship with the interchange connectivity value of that route. Results of the survey have shown that control beliefs of a traveller are only susceptible to change through improvement in the reliability of the transfer connection. In order to increase usage of routes with interchanges, the service should be designed to minimise the interchange time (interchange walking and waiting time) such that travellers do not feel anxious and disconnected from their travel. The maximum interchange time that is accepted by travellers is 10 minutes. Furthermore, results of the study have shown that perceived behavioural control is a strong antecedent of intention; once travellers feel more in control of their journey, their willingness to use routes with interchanges increases. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR174E Mon, 14 May 2012 14:00:00 UTCHomes are compositional in nature and they include both dwelling and location characteristics. The quality of the living depends on the housing, and different households value differently housing characteristics, depending on their needs and wants. However, recent investigations into residential location show that there is a component of preference heterogeneity that cannot be accounted for by the household structure. A latent class model approach is applied to examine the segmentation of the sampled households based on their lifestyle preferences. The paper examines the degree of association between the identified household life cycle segments and the estimated latent classes. The results indicate that composition of the latent structure is not the same for each household segment. While income and the age of the head of household appear to be the most discriminating demographic characteristics affecting housing preferences, these variables do not lead to the same latent class structure for household of different compositions. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR183E Mon, 14 May 2012 14:00:00 UTCWithin the stated choice literature there has been increasing interest in methods that close the gap being the experimental and experiential results of such studies. This is particularly true in the field of transportation, where many important policy decisions rely on such experiments being able to accurately forecast human behaviour. Capturing information on how information within stated choice experiments, attempting to increase the contextual realism of the decision under analysis and framing the survey itself such that it more accurately represents a real world decision environment are commonly scrutinized approaches. More recently the certainty index, whereby respondents report how certain they are about each choice they make, has been adopted as an alternative method of bridging the gap between the hypothetical and the real. This paper is the first in the transportation literature that jointly models both choice and certainty. Additional literature also posits that when making decisions, people first identify an acceptable set of alternatives that form their consideration set from which an ultimate choice is made. This paper also jointly estimates choice and alternative acceptability. In comparing choices of differing certainty, surprisingly little difference in marginal sensitivities are found. This is not the case in the alternative acceptability models however. An important finding of this research is that what could be interpreted as preference heterogeneity may in fact be more closely linked to scale. The ramifications of this on future research is discussed. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR186E Mon, 14 May 2012 14:00:00 UTCThis paper builds on previous regression-based approaches that endeavour to account for spatial effects underlying differences in vehicle kilometres of travel (VKT) by private vehicle. A multilevel modelling (MLM) approach is developed with the intent of isolating the variability in VKT attributable to various levels of geographic aggregation. The approach is applied to the prediction of VKT for the Sydney Statistical Division using information from a major household travel survey, supplemented with measures of accessibility, density, and land-use designed to capture different spatial influences. MLM null models show that around half the variation in VKT is attributable to effects at the higher spatial unit while the development of full models (i.e., with all the independent variables included) reduces the unexplained variance in VKT substantially. Diagnostics of model fit showed the MLMs offered small improvements over current OLS methods. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR190E Mon, 14 May 2012 14:00:00 UTCThis study examines the relationship between various weather conditions and commuter bicyclist volume in two cities (Portland, USA and Brisbane, Australia), which fall into different climatic zones. Investigating the variation in day-to-day bicycle ridership can help to understand factors influencing demand and in particular how base climatic conditions may condition bicyclist’s responsiveness to changes in weather and climate. Temporal variations in bicycle usage and key weather parameters (temperature and rainfall) are analyzed. Ridership counts and weather data are then used to develop an aggregate demand model that provides quantitative insight into the effects of weather on bicyclist volumes. The results indicate that daily bicyclist volume varies across hours of the day as well as days of the week. Both temperature and rainfall are found to have a significant influence on daily bicyclist volume but with different degrees of sensitivity in these two cities which correspond to their base climates. The results are discussed in view of their implications for government strategies that seek to increase the role of bicycle in urban areas. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR191E Mon, 14 May 2012 14:00:00 UTCTravel time is a vital performance index in assessing transportation network performance. Vehicle speeds along any network route fluctuate and route travel times are essentially random. This technical note first examines travel time modelling and estimation via the random modelling of speeds, and a general approach is presented for travel time estimation based on speed distributions. Since normal and log-normal distributions are commonly employed for speed modelling in traffic engineering, travel time estimation is further discussed in the paper with regard to both distributions. Most probability distributions (including normal and log-normal) assume that a modelled random variable spreads over the whole or half range of the real number axis, but, in practice, any traffic quantity of interest makes sense only within a limited value range. In view of this, the concept of truncated distributions is introduced, and, specifically, the probability features of truncated normal and log-normal distributions are explored in the paper with regard to the discussed travel time estimation issue. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR192E Mon, 14 May 2012 14:00:00 UTCSimilar to vehicular traffic, pedestrian movements having varied capabilities and body sizes can also be classified as heterogeneous. Vehicular traffic resolves the diversity issue by converting heterogeneous vehicle flow into an equivalent flow using passenger car equivalent (PCE) factors. Pedestrian flow analysis has yet to implicitly incorporate pedestrian diversity in the design of pedestrian facilities although some form of adjustment is suggested. This paper introduces the concept of PCE-type factors for mixed pedestrian traffic called standard pedestrian equivalent (SPE) factors. The SPE factors are estimated relative to the average commuter. The equivalent total travel time approach for PCE estimation was adapted to consider the effects of the differences in physical and operational characteristics of pedestrians particularly walking speed and body size. Pedestrian micro-simulation has been employed to evaluate hypothetical pedestrian proportions to generate corresponding flow relationships. Walking speeds and body sizes were varied across different flow conditions, walkway widths and proportions of other pedestrian types. The first part of the paper explores how the two pedestrian characteristics influence estimated SPE factors. The second part is a case study utilizing field collected data illustrating SPE factors calculated for older adults, obese pedestrians and their combination. An application of SPE factors demonstrates the robustness of the methodology in bridging the gap between pedestrian compositions and planning practice. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR200E Mon, 14 May 2012 14:00:00 UTCEnd of trip facilities can be a barrier that limits the potential of the bicycle as a commuter transport mode. In recent years there has been increasing interest in development of large cycle centers or bicycle arrival stations which provide secure bicycle storage, changing rooms, showers, lockers and repair facilities. This paper reports the results of an evaluation of a bicycle arrival station built on suburban university campus about 20 km from the CBD in Melbourne, Australia. Use of this un-staffed facility, which provides secure parking for 100 bicycles, is offered free of charge to staff and students. While users where generally satisfied with many features of the facility, concerns emerged over the adequacy of the towel drying facilities, the availability of lockers and the management of the locker facilities. Nearly half of the users indicated that they had switched from commuting by car to the bicycle as a result of access to the facility. In an absolute sense the impact of the facility on commuting to campus is small given that on a typical day during the semester it caters for 55 users and replaces about 52 motor vehicle trips. Measures to encourage greater use by staff throughout the year, and discourage lockers being captured by infrequent users, would help to increase its utilization. That would improve the cost effectiveness of providing facilities like this to stimulate bicycle use while simultaneously reducing car use and greenhouse gas emissions. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR209E Mon, 14 May 2012 14:00:00 UTCIn recent years we have seen an explosion of research seeking to understand the role that rules and heuristics might play in improving the predictive capability of discrete choice models, as well as delivering willingness to pay estimates for specific attributes that may (and often do) differ significantly from estimates based on a model specification that assumes all attributes are relevant. This paper adds to that literature in one important way - it explicitly recognises the endogeneity induced by attribute non-attendance and conditions attribute parameters on underlying unobserved attribute importance ratings. It develops a hybrid model system involving attribute processing and outcome choice models in which latent variables are introduced as explanatory variables in both parts of the model, explaining the answers to attribute processing questions and explaining heterogeneity in marginal sensitivities in the choice model. The resulting empirical model explains how lower latent attribute importance leads to a higher probability of indicating that an attribute was ignored or that it was ranked as less important, as well as increasing the probability of a reduced value for the associated marginal utility coefficient in the choice model. The model does this without risk of endogeneity bias or using the answers to information processing questions as error free explanatory variables. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR210E Mon, 14 May 2012 14:00:00 UTCDespite the widespread use of stated choice (SC) surveys with large numbers of choice sets, there remains a certain amount of unease about survey length, on the grounds that this potentially reduces respondent engagement, which could be interpreted as a result of fatigue or boredom. There is frequent reference to the findings of Bradley & Daly who showed a significant drop in utility scale, i.e. an increase in error, as a respondent moved from one choice experiment to the next, an effect they related to respondent fatigue. While the work by Bradley & Daly has become a standard reference in this context, it should be recognised that not only was the fatigue part of the work based on a single dataset, but the state-of-the-art and the state-of-practice in stated choice survey design and implementation has moved on significantly since their study. In this paper, we present a more comprehensive study investigating evidence of respondent fatigue across a larger number of different surveys. We provide strong evidence that the concerns about fatigue in the literature are possibly overstated, with no clear decreasing trend in scale across choice tasks in any of our studies, while evidence of significant attribute level (as opposed to scale) heterogeneity across choice tasks points suggests possible learning effects. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR328E Mon, 14 May 2012 14:00:00 UTCThis report describes new analysis of the 2010/11 annual survey of car club users conducted by Carplus, in order to understand the potential emission impacts of car clubs in London. The analysis shows that, on average, members of car clubs report substantially lower levels of household car use than the average London household with at least one full car license holder. Those who have just joined the car club are asked about their pre-joining travel behaviour, and, on average, this is also reported to involve substantially greater household car use than for established members. In addition, car club vehicles tend to be considerably newer and cleaner than the average private car. Consequently, average estimations of emissions of CO2, NOx and PM10 from car use by households with established London car club members are less than half of the equivalent emissions estimations for London households with at least one full car license holder, or for the pre-joining household car use by those who have recently joined. To establish the robustness of these results, different sub-groups of car club users were considered. This shows that, after joining, on average, there are increases in car use by non-car-owning households, and by households whose personal car ownership also increases. However, these increases are relatively small compared to the large average reductions in household car use by those who reduce their household car ownership – meaning that the overall average changes calculated seem robust. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR342E Mon, 14 May 2012 14:00:00 UTCThis paper presents the results of analysis of the CCT Evaluation Baseline Survey results by independent expert Nick Cavill in collaboration with the British Department for Transport social researchers. The analysis investigates the potential for delivering public health benefits through increasing cycling amongst different population groups. It then explores the size and characteristics of those groups to inform the targeting of cycling interventions. The results are relevant to local authorities who are making the case for investment in cycling, and considering how best to design schemes to realise the health benefits of cycling. http://114.111.144.247/ics-wpd/exec/icswppro.dll?AC=QUERY&TN=inroads&QY=find+RC+=+1205AR351E Mon, 14 May 2012 14:00:00 UTCThis study developed methods to assess the cost of travel time variability for air and car travellers. The cost of travel time variability can be determined in three steps. First, researchers need to develop a behavioural micro economic model that is able to capture travellers’ responses to travel time variability. Second, this model needs to be validated and calibrated using empirical data. Third, the model needs to be applied using observed or simulated travel time data in order to see how large the costs of travel time variability are.