| 1. |
- Gärling, Tommy, 1941
(författare)
-
Travel-related feelings : review, theoretical framework, and numerical experiments
- 2019
-
Ingår i: Transportation letters. - Oxon, England : Taylor & Francis. - 1942-7867 .- 1942-7875. ; 11:1, s. 54-62
-
Forskningsöversikt (refereegranskat)abstract
- Limited previous research shows that travel by different modes evokes feelings. Also after-effects due to stress have been observed. Such travel-related feelings are important to consider in transport planning because of their possible consequences for travelers' emotional well-being. A theoretical framework is proposed that makes quantitative predictions of the impacts of transient feelings (emotional responses) on enduring feelings (current mood) with consequences during and after travel. Positive and negative emotional responses are posited to be evoked by transient critical incidents (e.g. disruptions) and non-transient factors (e.g. noise) during travel. Numerical experiments illustrate the quantitative predictions on current mood during and after travel for both types of evoking factors.
|
|
| 2. |
- Haghani, Milad, et al.
(författare)
-
How COVID-19 transformed the landscape of transportation research: an integrative scoping review and roadmap for future research
- 2024
-
Ingår i: Transportation Letters. - : Informa UK Limited. - 1942-7867 .- 1942-7875. ; 16:1, s. 43-88
-
Forskningsöversikt (refereegranskat)abstract
- In the wake of the COVID-19 pandemic, scholars mobilized their efforts to address its far-reaching societal problems. With mobility restrictions being front and center of the pandemic, a new cohort of transportation science was developed within a short period of time. Here, we examine more than 400 studies related to COVID-19 published across transportation journals during 2020 and 2021. The aim is (i) to scope this newly developed segment of transportation research, (ii) outline the diversity of pandemic-related issues across various divisions of the transportation field and (iii) provide a roadmap for the future of this line of research. Common themes are identified and existing congruence and discrepancies across findings are discussed. Results show that although conventional methods of transportation research were adopted in virtually all COVID-19 studies, no pre-pandemic study was particularly instrumental in the development of this segment of transportation literature. The COVID-19 segment appears to have developed its own independent knowledge foundation, in that, it does not systemically and frequently look back at any particular pre-pandemic reference. Potential impacts of this newly developed segment on the metrics of transportation journals are quantified and discussed.
|
|
| 3. |
- He, Yixu, et al.
(författare)
-
Exploring the design of reward functions in deep reinforcement learning-based vehicle velocity control algorithms
- 2024
-
Ingår i: Transportation Letters. - 1942-7867 .- 1942-7875. ; In Press
-
Tidskriftsartikel (refereegranskat)abstract
- The application of deep reinforcement learning (DRL) techniques in intelligent transportation systems garners significant attention. In this field, reward function design is a crucial factor for DRL performance. Current research predominantly relies on a trial-and-error approach for designing reward functions, lacking mathematical support and necessitating extensive empirical experimentation. Our research uses vehicle velocity control as a case study, build training and test sets, and develop a DRL framework for speed control. This framework examines both single-objective and multi-objective optimization in reward function designs. In single-objective optimization, we introduce “expected optimal velocity” as an optimization objective and analyze how different reward functions affect performance, providing a mathematical perspective on optimizing reward functions. In multi-objective optimization, we propose a reward function design paradigm and validate its effectiveness. Our findings offer a versatile framework and theoretical guidance for developing and optimizing reward functions in DRL, particularly for intelligent transportation systems.
|
|
| 4. |
- Hess, Stephane, et al.
(författare)
-
Understanding attitudes towards congestion pricing : a latent variable investigation with data from four cities
- 2019
-
Ingår i: Transportation letters. - : TAYLOR & FRANCIS LTD. - 1942-7867 .- 1942-7875. ; 11:2, s. 63-77
-
Tidskriftsartikel (refereegranskat)abstract
- Numerous cities around the world are considering the implementation of road pricing to ease urban traffic congestion, following on from the success in cities such as London and Singapore. However, policy-makers are also all too aware of the generally negative public opinion toward such measures. This study makes use of data collected in four cities (two in Sweden, one in Finland, and one in France) using a very consistent survey probing for citizens' attitudes toward pricing. We find very strong similarities across the four cities in terms of a number of underlying attitudinal constructs that help explain people's answers in a hypothetical referendum on congestion pricing. The similarities across cities indicate that the increase in the opinion toward congestion pricing once they are introduced is not primarily an effect of changes in underlying attitudes, changes in how the underlying attitudes influence the support for congestion pricing, or differences in anticipated versus experienced or perceived self-interest. Instead, this effect seems to be caused by a status quo acceptance, tending to increase the support for the current situation.
|
|
| 5. |
- Kazemzadeh, Khashayar, et al.
(författare)
-
Same questions, different answers? A hierarchical comparison of cyclists’ perceptions of comfort: in-traffic vs. online approach
- 2021
-
Ingår i: Transportation Letters. - : Informa UK Limited. - 1942-7867 .- 1942-7875. ; 13:7, s. 531-539
-
Tidskriftsartikel (refereegranskat)abstract
- This study was aimed at comparing cyclists’ perceptions of comfort when in traffic and when online. Questions about comfort were structured according to three hierarchical levels, namely strategic (city level), tactical (frequent route level) and operational (survey spot level). The purpose is to understand how the cyclists’ perceptions of comfort at different levels vary between questionnaire administration methods. The results suggest that cyclists are more positive and optimistic about the cycling comfort when answering online questionnaires than when answering in-traffic questionnaires, but only when the questions refer to the operational level (at a more general level, their answers were not statistically different). Cycling planners and researchers could incorporate these findings in their data collection policies by selecting online approaches, which are generally less expensive than but equally effective as in-traffic approaches, when carrying out studies that concern the strategic and/or tactical levels of comfort.
|
|
| 6. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
-
Representing travel cost variation in large-scale models of long-distance passenger transport
- 2022
-
Ingår i: Transportation letters. - : Taylor & Francis. - 1942-7867 .- 1942-7875. ; :7, s. 778-786
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we show that cost variation for long-distance travel is often substantial and we discuss why it is likely to increase further in the future. Thus, the current practice in large-scale models, to set one single travel cost for a combination of origin, destination, mode, and purpose, has potential for improvement. To tackle this issue, we develop ways of accounting for cost variation in model estimation and forecasting. For public transport, two approaches are proposed. The first method focusses on improving the average fare, whereas the second approach incorporates a submodel for choice of fare alternative within a demand model structure. Only the second method is consistent with random utility theory. For car, cost variation is related to long run decisions such as car type choice. Handling car cost variation therefore implies considering car type choice. This long-term choice can be considered using a car fleet model. © 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
|
|
| 7. |
- Shafabakhsh, G., et al.
(författare)
-
Pedestrians' mental satisfaction's relationship with physical characteristics on sidewalks using analytical hierarchy process: case study of Tehran, Iran
- 2015
-
Ingår i: Transportation Letters. - : Informa UK Limited. - 1942-7867 .- 1942-7875. ; 7:3, s. 121-132
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of the current study is an examination of the relationship between the existing physical characteristics of sidewalks in Tehran, Iran, and pedestrians' mental satisfaction. In order to successfully achieve this, physical and mental sidewalk characteristics were determined via expert elicitation and pedestrian investigations. Subsequently, 40 photographs of sidewalks located in Tehran were selected from all taken images, based upon photographic techniques; these were used to elicit data from 514 respondents via formally developed questionnaires. An analytical hierarchy process (AHP) was employed to analyze collated data. Results indicate that mental satisfaction is directly correlated with observed physical condition of sidewalks. It is concluded that sensitivity analyses such as those used in this study may be suitable for future optimization of sidewalk construction and maintenance; the presented approach may represent an appropriate model for increasing pedestrians' satisfaction and is thus potentially of use to urban and peri-urban planners.
|
|
| 8. |
- Shaoyang, Zhang, et al.
(författare)
-
Image enhancement on fractional differential for road traffic and aerial images under bad weather and complicated situations
- 2014
-
Ingår i: Transportation letters. - 1942-7867 .- 1942-7875. ; 6:4, s. 197-205
-
Tidskriftsartikel (refereegranskat)abstract
- To enhance road traffic images and aerial images in bad weather, a new fractional differential operator is studied, and it is different from the traditional Tiansi operator. In the operator, for any sized kernel, the coefficient at the center position is not a constant, and it is the function of the fractional order and the kernel size; for the other pixels in the kernel, there is no zero coefficient value, and the values of the coefficients are calculated according to the distances from the center position on the basis of fractional differential. In experiments, a number of images are tested, and the results show that the studied operator is suitable for the vague images of the low contrast and rich textures, with less color changes. When compared with other newly proposed algorithms (e.g. Dark channel prior and Multiple scale Retinex, etc.) it performs better in some cases.
|
|
| 9. |
|
|
