Examination of Clusters for Better Understanding Commuter Cyclists’ Travel Behavior: Insights from a Longitudinal Panel Survey

2017 ◽  
Vol 2665 (1) ◽  
pp. 40-50 ◽  
Author(s):  
Farhana Ahmed ◽  
Geoff Rose ◽  
Christian Jakob ◽  
Md. Rashedul Hoque
Keyword(s):  
Travel Behavior ◽  
Weather Conditions ◽  
Motivational Factors ◽  
Situational Factors ◽  
Parameter Estimates ◽  
Work Characteristics ◽  
Panel Survey ◽  
Long Distance ◽  
Adverse Weather ◽  
Part Time

This study examined commuter cyclists’ travel behavior, particularly in response to changes in weather conditions and situational factors. The motivators, deterrents, and preferences of commuter cycling were also examined. To reach greater understanding of commuter cyclists’ decision making, cyclists were clustered. Disaggregated travel data were collected from a longitudinal panel survey (sample size: 355) and analyzed to identify the influence of weather conditions and situational factors on commuters’ day-to-day cycling decisions. The baseline survey (a one-off survey) provided information about the work characteristics, travel characteristics, motivational factors, and sociodemographics of the participants. Generalized estimating equations were used to compare the responses between groups on the day-to-day influences of weather conditions and situational factors. Binary logistic regression was used to predict commuters’ cycling decisions (whether or not to cycle). Commuter cyclists’ average decision (over the longitudinal survey period) was modeled with work characteristics, travel characteristics, motivational factors, and sociodemographics as explanatory variables. The results indicate that parameter estimates vary significantly between groups. Part-time commuter cyclists and commuter cyclists who do not plan their travel behavior in advance were more affected by adverse weather conditions than were the comparison groups. Situational factors were larger deterrents for part-time commuter cyclists and cyclists who traveled longer distances to work. However, off-road paths encouraged long-distance commuters to cycle more often. The paper includes a discussion on how the implications of these results can influence government policies and strategies in an effort to increase commuter cycling.

Gendered Experiences of Mobility

Transfers ◽  
2013 ◽  
Vol 3 (3) ◽  
pp. 79-98 ◽  
Author(s):  
Shahnaz Huq-Hussain ◽  
Umme Habiba
Keyword(s):  
Middle Class ◽  
Travel Behavior ◽  
Weather Conditions ◽  
Capital City ◽  
Mobility Patterns ◽  
Security Issues ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
The City ◽  
Detailed Picture

This article examines the travel behavior of middle-class women in Dhaka, the capital city of Bangladesh and one of the world's largest and most densely populated cities. In particular, we focus on women's use of non-motorized rickshaws to understand the constraints on mobility for women in Dhaka. Primary research, in the form of an empirical study that surveyed women in six neighborhoods of Dhaka, underpins our findings. Our quantitative and qualitative data presents a detailed picture of women's mobility through the city. We argue that although over 75 percent of women surveyed chose the rickshaw as their main vehicle for travel, they did so within a complex framework of limited transport options. Women's mobility patterns have been further complicated by government action to decrease congestion by banning rickshaws from major roads in the city. Our article highlights the constraints on mobility that middle-class women in Dhaka face including inadequate services, poorly maintained roads, adverse weather conditions, safety and security issues, and the difficulty of confronting traditional views of women in public arenas.

Investigating the Temporal Instability in Injury Severity Outcomes of Clear and Adverse Weather Crashes on Rural Mountainous Highways

2021 ◽  
pp. 036119812110570
Author(s):  
Irfan U. Ahmed ◽  
Mohamed M. Ahmed
Keyword(s):  
Monte Carlo ◽  
Injury Severity ◽  
Statistical Significance ◽  
Weather Conditions ◽  
Warning Signs ◽  
Parameter Estimates ◽  
Connected Vehicle ◽  
Temporal Instability ◽  
Short Period ◽  
Adverse Weather

Analysis of driver injury severity based on weather conditions on rural highways is limited in the literature. Such analyses provide insights useful to policymakers in optimizing the allocation of limited resources based on weather conditions. Furthermore, if there is a possibility of factors exhibiting temporal instability, then an aggregate analysis can lead to erroneous allocation of funds. In this study, separate models for clear and adverse weather conditions were developed for each of the years from 2015 to 2019 using crash data from a rural mountainous highway corridor. A random-intercept Bayesian logistic approach was used to analyze the dichotomous injury severity response and capture the between-crash variance. An efficient Markov chain Monte Carlo sampling technique known as the No-U-Turn Hamiltonian Monte Carlo was employed to sample the posterior distributions of parameter estimates. Likelihood ratio tests provided statistical significance of the temporal instability and also the differences in driver injury severities resulting from clear and adverse weather crashes. While most of the variables demonstrated temporal instability, some factors exhibited temporal stability over a short period of time and only during clear weather conditions. Findings from the separate models suggest that there are major differences in both the combination and magnitude of the significant contributing factors. Implementation of confirmatory warning signs, variable message signs, connected vehicle technology, strict enforcements during different times and locations, and driver awareness programs have been recommended as suitable countermeasures. The findings and recommendations could potentially help in guiding the respective agencies in formulating injury severity mitigation policies and strategies.

Multivariate Poisson Lognormal Modeling of Weather-Related Crashes on Freeways

2018 ◽  
Vol 2672 (38) ◽  
pp. 184-198 ◽  
Author(s):  
Kai Wang ◽  
Shanshan Zhao ◽  
Eric Jackson
Keyword(s):  
Model Prediction ◽  
Prediction Models ◽  
Weather Conditions ◽  
Parameter Estimates ◽  
Prediction Ability ◽  
Crash Prediction ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
Crash Prediction Models ◽  
Crash Types

Adverse weather conditions are one of the primary causes of motor vehicle crashes. To identify the factors contributing to crashes during adverse weather conditions and recommend cost-effective countermeasures, it is necessary to develop reliable crash prediction models to estimate weather-related crash frequencies. To account for the variations in crash count among different adverse weather conditions, crash types, and crash severities for both rain- and snow-related crashes, crash data on freeways was collected from the State of Connecticut, and crash prediction models were developed to estimate crash counts by crash type and severity for each weather condition. To account for the potential correlations among crash type and severity counts due to the common unobserved factors, integrated nested Laplace approximation (INLA) multivariate Poisson lognormal (MVPLN) models were developed to estimate weather-related crashes counts by crash type and severity simultaneously (four MVPLN models were estimated in total). To verify the model prediction ability, univariate Poisson lognormal (UPLN) models were estimated and compared with the MVPLN models. The results show that the effects of factors contributing to crashes, including median width, horizontal curve, lane width, and shoulder width, vary not only among different adverse weather conditions, but also among different crash types and severities. The crash types and severities are shown to be highly correlated and the model comparison verifies that the MVPLN models significantly improve the model prediction accuracy compared with the UPLN models. Therefore, the MVPLN model is recommended to provide more unbiased parameter estimates when estimating weather-related crashes by crash type and severity.

scholarly journals Defining catchment origins of a geographical bottleneck: Implications of population mixing and phenological overlap for the conservation of Neotropical migratory birds

The Condor ◽  
2020 ◽  
Vol 122 (2) ◽  
Author(s):  
Laura Cardenas-Ortiz ◽  
Nicholas J Bayly ◽  
Kevin J Kardynal ◽  
Keith A Hobson
Keyword(s):  
Migratory Birds ◽  
Geographical Area ◽  
Weather Conditions ◽  
Neotropical Migrants ◽  
Long Distance ◽  
Catharus Ustulatus ◽  
Yellow Warbler ◽  
Population Mixing ◽  
Temporal Segregation ◽  
Adverse Weather

Abstract Migratory bottlenecks concentrate individuals and populations of Nearctic–Neotropical migrants from across vast breeding areas. The extent to which such concentrations occur has important ramifications for interpreting migratory connectivity and for the vulnerability of populations throughout the annual cycle but investigations of such phenomena are rare. We inferred breeding origins of 11 species of Nearctic–Neotropical migrants captured during fall migration in the Darién region, northwestern Colombia, using feather stable-hydrogen isotope values (δ 2Hf). Our objectives were to determine (1) the extent to which this region acts as a catchment for individuals from across a species’ breeding range, (2) if temporal patterns of arrival arise as a function of migration distance inferred from δ 2Hf, and (3) if phenological differences among species segregate populations. The Darién concentrated populations of 6 species, with individuals potentially derived from 78% to 94% of their respective North American breeding ranges. The catchment area for the remaining 5 species covered 40–72% of breeding ranges, with a bias in origin from the west (e.g., Northern Waterthrush [Parkesia noveboracensis], Swainson’s Thrush [Catharus ustulatus]), north or center (Yellow Warbler [Setophaga petechia]) of their range. Differential timing in the migration of populations occurred in 6 species, generating a degree of temporal segregation. In contrast, peak migration for all species occurred in October, resulting in high overlap among species in their use of the Darién. Overall, our results describe high mixing of populations in the Darién for several species, which, given the region’s highly restricted geographic extent, suggests that a bottleneck effect occurs; however, comparisons with other regions in Central America and northern South America are required. The combination of extensive population mixing and limited temporal segregation over a narrow geographical area suggests that long-distance migrants may be especially vulnerable to events occurring in such regions, including adverse weather conditions and anthropogenic land cover change.

Electric Vehicle Charger Placement Optimization in Michigan Considering Monthly Traffic Demand and Battery Performance Variations

2021 ◽  
pp. 036119812098195
Author(s):  
Fatemeh Fakhrmoosavi ◽  
MohammadReza Kavianipour ◽  
MohammadHossein (Sam) Shojaei ◽  
Ali Zockaie ◽  
Mehrnaz Ghamami ◽  
...  
Keyword(s):  
Optimal Allocation ◽  
Critical Factor ◽  
Cold Weather ◽  
Contributing Factors ◽  
Modeling Framework ◽  
Long Distance ◽  
Charging Infrastructure ◽  
Traffic Demand ◽  
Adverse Weather ◽  
Performance Variations

Limited charging infrastructure for electric vehicles (EVs) is one of the main barriers to adoption of these vehicles. In conjunction with limited battery range, the lack of charging infrastructure leads to range-anxiety, which may discourage many potential users. This problem is especially important for long-distance or intercity trips. Monthly traffic patterns and battery performance variations are two main contributing factors in defining the infrastructure needs of EV users, particularly in states with adverse weather conditions. Knowing this, the current study focuses on Michigan and its future needs to support the intercity trips of EVs across the state in two target years of 2020 and 2030, considering monthly traffic demand and battery performance variations. This study incorporates a recently developed modeling framework to suggest the optimal locations of fast EV chargers to be implemented in Michigan. Considering demand and battery performance variations is the major contribution of the current study to the proposed modeling framework by the same authors in the literature. Furthermore, many stakeholders in Michigan are engaged to estimate the input parameters. Therefore, the research study can be used by authorities as an applied model for optimal allocation of resources to place EV fast chargers. The results show that for charger placement, the reduced battery performance in cold weather is a more critical factor than the increased demand in warm seasons. To support foreseeable annual EV trips in Michigan in 2030, this study suggests 36 charging stations with 490 chargers and an investment cost of $23 million.

scholarly journals Ship Handling in Unprotected Waters: A Review of New Technologies in Escort Tugs to Improve Safety

2021 ◽  
Vol 2 (1) ◽  
pp. 46-62
Author(s):  
Santiago Iglesias-Baniela ◽  
Juan Vinagre-Ríos ◽  
José M. Pérez-Canosa
Keyword(s):  
High Performance ◽  
New Technologies ◽  
Weather Conditions ◽  
Hull Form ◽  
Best Available Technologies ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
New Type ◽  
Technological Challenge ◽  
And Performance

It is a well-known fact that the 1989 Exxon Valdez disaster caused the escort towing of laden tankers in many coastal areas of the world to become compulsory. In order to implement a new type of escort towing, specially designed to be employed in very adverse weather conditions, considerable changes in the hull form of escort tugs had to be made to improve their stability and performance. Since traditional winch and ropes technologies were only effective in calm waters, tugs had to be fitted with new devices. These improvements allowed the remodeled tugs to counterbalance the strong forces generated by the maneuvers in open waters. The aim of this paper is to perform a comprehensive literature review of the new high-performance automatic dynamic winches. Furthermore, a thorough analysis of the best available technologies regarding towline, essential to properly exploit the new winches, will be carried out. Through this review, the way in which the escort towing industry has faced this technological challenge is shown.

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