Modelling activity-travel behaviour dynamics with panel data: The state-of-the-art

The field of travel behaviour dynamics represented a vibrant research area in the 1980s and the 1990s (Golob & Meurs, 1987; Golob, Kitamura, & Long, 1997; Kitamura, 1990), but has since, probably due to lack of mobility panel data, received relatively little attention by transportation researchers. Nevertheless, through the use of panel data (repeated measures of the same individuals) many new insights may be gained with respect to travel behaviour, insights that are fundamentally different from those that can possibly be gained from cross-sectional data

Life cycle economic and environmental impacts of cdw recycled aggregates in roadway construction and rehabilitation

The use of recycled materials in roadway construction and rehabilitation can achieve significant benefits in saving natural resources, reducing energy, greenhouse gas emissions and costs. Construction and demolition waste (CDW) recycled aggregate as an alternative to natural one can enhance sustainability benefits in roadway infrastructure. The objective of this study was to quantitatively assess the life cycle economic and environmental benefits when alternative stabilizedCDW aggregates are used in pavement construction. Comparative analysis was conducted on a pavement project representative of typical construction practices in northern Italy so as to quantify such benefits. The proposed alternative sustainable construction strategies considered CDW aggregates stabilized with both cement and cement kiln dust (CKD) for the base layer of the roadway. The life cycle assessment results indicate that using CDW aggregate stabilized with CKD results in considerable cost savings and environmental benefits due to (i) lower energy consumption and emissions generation during material processing and (ii) reduction in landfill disposal. The benefits illustrated in this analysis should encourage the wider adoption of stabilized CDW aggregate in roadway construction and rehabilitation. In terms of transferability, the analysis approach suggested in this study can be used to assess the economic and environmental benefits of these and other recycled materials in roadway infrastructure elsewhere

Investigating social media spatiotemporal transferability for transport

Social Media have increasingly provided data about the movement of people in cities making them useful in understanding the daily life of people in different geographies. Particularly useful for travel analysis is when Social Media users allow (voluntarily or not) tracing their movement using geotagged information of their communication with these online platforms. In this paper we use geotagged tweets from 10 cities in the European Union and United States of America to extract spatiotemporal patterns, study differences and commonalities among these cities, and explore the nature of user location recurrence. The analysis here shows the distinction between residents and tourists is fundamental for the development of city-wide models. Identification of repeated rates of location (recurrence) can be used to define activity spaces. Differences and similarities across different geographies emerge from this analysis in terms of local distributions but also in terms of the worldwide reach among the cities explored here. The comparison of the temporal signature between geotagged and non-geotagged tweets also shows similar temporal distributions that capture in essence city rhythms of tweets and activity spaces

Behavioural micro-dynamics of car ownership and travel in the Seattle metropolitan region from 1989 to 2002

In this paper data from 230 households observed in ten different occasions (waves) from 1989 to 2002 in the Puget Sound region are used to explore relationships among number of cars owned, number of trips driving alone, and number of trips sharing cars with household members. Using a mixture latent class Markov model we identify four distinct groups that are a High Mobility group with more cars and car trips, an Average Mobility group with lower car ownership and trips driving alone, a third group with relatively high car ownership but few car sharing trips, and a fourth group of Low Mobility characterized by the low car ownership and trips. Households change behaviour adapting to internal and external changes to their environment but they also anticipate changes and go through a "preparation" stage (e.g., adding another car in their fleet in expectation of adding another employed person). Land use plays a somewhat secondary role. The analysis also reveals three classes (hidden Markov chains) of households underlying behavioural dynamics with increases in the low car ownership categories (zero and one car per household), decreases in the high car ownership (three cars and four or more cars per household) and stable behaviour in the two cars per household group. Household membership in these classes is significantly influenced by householder ratings to parking availability, schedule flexibility, bus transfers, and day-to-day costs of driving. The findings here show attitudes and land use enhance understanding of longitudinal heterogeneity

Spatial analysis of access to and accessibility to surrounding train stations: a case study of accessibility for the elderly in Perth, Western Australia

Approximately one-fifth of Perth’s population is aged 60 or older. Projections suggest that this proportion will continue to increase as a result of the large number of children born after the World War II (1946–1964). Access to and accessibility around train stations for the aging population is and will become a more important issue as the elderly population continues to grow. The aim of the paper is to develop and apply anew measure of accessibility to train stations at a fine spatial scale, justified by the special circumstance of the elderly using a case study in Perth, Western Australia. Intercept surveys are used to collect data on factors affecting train station accessibility for patrons aged 60 years or older, at seven highly dispersed train stations. Overall accessibility is measured separately using a composite index based on three travel modes (walk-and-ride, park-and-ride and bus-and-ride). The results illustrate that key variables, such as distance from an origin to a station, walking or driving route directness, land-use diversity, service and facility quality, bus connection to train stations, all affect the accessibility to train stations for the elderly. This implies that improvements to these factors will improve accessibility for this population group

Integrated Land Use-Transport Model System with Dynamic Time-Dependent Activity-Travel Microsimulation

The development of integrated land use-transport model systems has long been of interest because of the complex interrelationships between land use, transport demand, and network supply. This paper describes the design and prototype implementation of an integrated model system that involves the microsimulation of location choices in the land use domain, activity-travel choices in the travel demand domain, and individual vehicles on networks in the network supply modeling domain. Although many previous applications of integrated transport demand-supply models have relied on a sequential coupling of the models, the system presented in this paper involves a dynamic integration of the activity-travel demand model and the dynamic traffic assignment and simulation model with appropriate feedback to the land use model system. The system has been fully implemented, and initial results of model system runs in a case study test application suggest that the proposed model design provides a robust behavioral framework for simulation of human activity-travel behavior in space, time, and networks. The paper provides a detailed description of the design, together with results from initial test runs

Characterization of rubberized cement bound aggregate mixtures using indirect tensile testing and fractal analysis

The main focus of this paper is to investigate the tensile properties of virgin and rubberized cement bound granular mixtures. This was conducted using indirect tensile testing with lateral displacement measurements, nondestructive resonant frequency testing, X-ray CT and quantitative assessment for cracking pattern using fractal analysis. The investigated properties were density, compacity, indirect tensile strength (ITS), indirect tensile static modulus, toughness, dynamic modulus of elasticity, dynamic modulus of rigidity, dynamic poison’s ratio, fractal dimension and fracture energy. To keep the same aggregate packing, the natural aggregate was replaced by waste tyres’ crumb rubber of similar gradation. Four volumetric replacement percentages (0%, 15%, 30% and 45%) of the 6 mm fraction size were utilized. This adjustment was observed to affect the material density not only due to the lower specific gravity, but because it also affects the compactibility of the mixture negatively due to the damping action of the rubber particles. In addition, strength was also affected detrimentally. However, material toughness was improved and stiffness was mitigated. The latter findings were supported by quantitative assessment of the cracking pattern which revealed more tortuosity and a higher fractal dimension as a result of rubber content increasing. A failure mechanism for this type of mixture was suggested and support by examining the internal structure of failed samples using X-ray CT. Overall, construction of cement-stabilized aggregate base with a small percentage of added crumb rubber may ensure a more sustainable and environmental-friendly pavement material and, at the same time, improve the properties of stabilized layers. However, behaviour of these mixtures under cyclic loading and evaluation of their durability should be assessed to fully validate their use

Vertical Equity Statewide Pilot, Data Inventory, and Guidelines for Performance Based Planning (VESPI) [Brief]

Existing accessibility indicators and destination attractiveness indicators fail to capture the character of destinations where people participate in activities. One reason this happens is due to computation of accessibility and destination attractiveness at aggregate levels. We test in this project the feasibility and usefulness of fine spatial and temporal resolution and develop a new set of performance and behavioral indicators that capture timing and duration of activities as well as commuting travel time