Using microscopic video data measures for driver behavior analysis during adverse winter weather: opportunities and challenges

ABSTRACT: This paper presents a driver behavior analysis using microscopic video data measures including vehicle speed, lane-changing ratio, and time to collision. An analytical framework was developed to evaluate the effect of adverse winter weather conditions on highway driving behavior based on automated (computer) and manual methods. The research was conducted through two case studies. The first case study was conducted to evaluate the feasibility of applying an automated approach to extracting driver behavior data based on 15 video recordings obtained in the winter 2013 at three different locations on the Don Valley Parkway in Toronto, Canada. A comparison was made between the automated approach and manual approach, and issues in collecting data using the automated approach under winter conditions were identified. The second case study was based on high quality data collected in the winter 2014, at a location on Highway 25 in Montreal, Canada. The results demonstrate the effectiveness of the automated analytical framework in analyzing driver behavior, as well as evaluating the impact of adverse winter weather conditions on driver behavior. This approach could be applied to evaluate winter maintenance strategies and crash risk on highways during adverse winter weather conditions

Analysing cyclist behaviour at cycling facility discontinuities using video data

RÉSUMÉ: The primary purpose of any transportation network is to provide connectivity between the origin and travel destination. However, given the vehicle oriented structure of the road network in many countries, there are connectivity issues in the cycling network, which has been implemented later. Discontinuities are physical interruptions in the cycling network where cyclists are faced with unexpected situations such as the end of a cycling facility or the change from one facility type to another that are perceived as inconvenient and less safe. The microscopic behaviour of cyclists and the risks they face at these points of discontinuity has not been extensively investigated in the literature. This study aims to evaluate the challenges faced by cyclists at discontinuities by observing cyclist behaviour at these locations and comparing them to control sites using automated video analysis techniques. Our methodology allows the extraction of valuable microscopic data for evaluation of cyclist behaviour at any location. The methodology is applied to a case study of four sites in Montreal, Canada. Using a set of discontinuity measures proposed in a previous work and applied to Montreal’s cycling network, video data was collected from a pole-mounted camera at locations with discontinuity and control sites. After extracting road user trajectories from the video data, a trajectory clustering algorithm was applied to find cyclists’ motion patterns and the various maneuver strategies adopted by cyclists. Speeds and acceleration statistics are extracted and compared between different motion patterns and between discontinuity and control sites. Results show that cyclists undertake a larger number of maneuvers at points of discontinuity compared to their control sites, and that both cyclist accelerations and speeds exhibit larger variations at discontinuities compared to larger and more stable speeds at control sites

IAA : Información y actualidad astronómica (9)

Sumario : Investigación: Las colas de polvo de los cometas.-- Agua en el Universo.-- Ventana Abierta: Sobre la enseñanza de la ciencia en la educación secundaria.-- Charlas con… Max Pettini.-- Actualidad Científica: La luz y los colores de las nebulosas planetarias.-- Magnetares.-- Actividades IAA.-- Agenda.Esta revista se publica con la ayuda de la Acción Especial DIF 2001-4284-E del Programa Nacional de Difusión de la Ciencia y la Tecnología, del Ministerio de Ciencia y Tecnología.Peer reviewe

Are Gasoline Demand Elasticities Different across Cities?

In this paper, we examine the heterogeneity in gasoline demand price and income elasticities across 40 cities in the province of Quebec Canada using quarterly data over the 2004 to 2009 period. We reject the hypothesis of identical elasticities across markets. However, the range of values for the price elasticity, between -0.65 and -0.14, is relatively narrow and confirms that the demand for gasoline is price inelastic. We find evidence that the average price and income elasticity is somewhat larger in markets with public transportation. Furthermore, these markets experience a strong declining trend in gasoline use per capita

Evaluating the effects of land use and strategies for parking and transit supply on mode choice of downtown commuters

JTLU vol 5, no 2, pp 103-119 (2012)Metropolitan regions around the world are looking for sustainable strategies to reduce motor-vehicle traffic congestion, energy consumption, and emissions. These strategies include land-use policies as well as improvements to public transit services. This empirical work aims at studying the potential impact of land use (LU), public transit supply (PT), and parking pricing strategies on the mode choice of commuters living in the commuter rail line catchments in the Montreal (Canada) region. It makes use of an econometric modeling approach with both transportation mode choice and neighborhood type choice as simultaneous decisions, in order to take into account the endogeneity of these choices. The neighborhood choices are represented by neighborhood typologies derived from a cluster analysis using land use and transit supply indicators (population density, land use mix, and bus transit supply). As part of the outcomes of this study, the elasticities of mode choice with respect to commuter-transit fees, travel time reductions, and hourly parking costs are estimated. From the results, it is observed that a reduction of 10 percent in the transit fee or relative travel time would increase mode split by 10 percent and 3 percent respectively. The effect of age on both mode choice and neighborhood choice is also estimated. e individual and household structure factors associated with mode choice and/or residential neighborhood choice are also identified. Commuter age affects both outcomes. Income and gender affect mode choice while car ownership and the presence of children are linked to neighborhood choice

Modeling the Effect of Land Use on Activity Spaces

Historically, when analyzing the effect of land-use on transportation demand, research has 2 concentrated on a few key indicators, notably mode choice, VMT and number of trips. At the 3 same time, this literature has primarily focused on the effects of individual land-use variables: 4 e.g. what is the effect of land-use mixity or population density on mode choice. It is becoming 5 increasingly clear however that the isolated impact of particular measures of land-use on 6 individual and household transportation behavior is small, but that when dealt with using a 7 clustered approach, their combined influence becomes both less ambiguous in direction and 8 greater in magnitude. This paper contributes to the transportation and land-use literature by 9 examining the effect of clusters of land-use indicators on activity spaces, an emerging but 10 traditionally ignored, transportation behavior indicator. Regression analysis results point to a 11 significant relationship between large and dispersed activity spaces, low levels of population and 12 employment density, and low levels of public transit accessibility and land use mix