| 1. |
- Hassner, Karin, et al.
(författare)
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Accidents between cyclists and heavy vehicles turning right : conflict and behavioral studies in intersections in central Stockholm
- 2016
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Konferensbidrag (refereegranskat)abstract
- This study aimed to find ways to decrease the risk for severe accidents between cyclists and heavy vehicles turning right. The primary question was whether the so called “Dutch” intersection design (with a protecting curb) could decrease the risks. Other questions were if there are other/better methods/designs and if there will be new serious risks with the Dutch design. The result from this study is that the Dutch design doesn't protect from accidents between cars turning right and cyclist. The reason for this is that these accidents mainly involve cyclists going straight. The best designs are where right turning cars have red signal while cyclists going straight have green signal. Other good solutions are bicycle lane together with bicycle box or set-back stop line for the cars. Bicycle tracks should transform into lanes when approaching an intersection. The study not only found that the Dutch design is a poor design to protect from car/bicycle accidents; it also brings new risks for accidents between cyclists and pedestrians.
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| 2. |
- Andersson, Matts, 1975-
(författare)
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Policy Analysis for Different Types of Decision-Making Situations
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis seeks to contribute to decision support for policy makers in the transport sector. In order to frame the papers and to relate them to the broad field of “policy analysis”, I have structured the papers around a simple framework with three decision levels: responsibility, policy gap, and policy measure. The thesis contains five papers.“Transaction and transition costs during the deregulation of the Swedish Railway market” is a paper in the transaction cost school. We studied the costs associated with the shift from monopoly to competition in the Swedish railway market, and we found that the change resulted in comparatively small transaction costs, but that transition and misalignment costs seem to be larger. In “Parking policy under strategic interaction”, I examined the effect of strategic interaction between jurisdictions using an analytical model based on Hotelling’s linear city model. I conclude that the procedure for setting supply in most municipalities has a strong downward effect on municipal parking fees and that resource flow competition implies that the fees are higher than the efficient prices (but that the effect of the supply procedures makes this effect incongruous).In “Validation of aggregate reference forecasts for passenger transport”, we followed up the Swedish national forecasts for passenger transport produced from 1975 to 2009 and tried to explain the deviations. We found that the forecasts during the last decades have overestimated car traffic, and that this is due to input errors. The potential problem of using cross-sectional models for forecasting intertemporal changes seems to have been limited.In “The kilometer tax and Swedish industry - effects on sectors and regions”, we estimated factor demand elasticities in the Swedish manufacturing industry and used these to analyze the effects of a kilometer tax for heavy goods vehicles. We found that the kilometer tax leads to factor substitution in that it decreases transport demand and increases labor demand. The effects on output are less pronounced. In “The effect of minimum parking requirements on the housing stock”, we used a model of the rental, asset, and construction markets. We quality-assured our assumptions and our results through interviews with market actors. In our example suburb, we found that parking norms reduced the housing stock by 1.2% and increased rents by 2.4%.
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| 4. |
- Berggren, Ulrik, et al.
(författare)
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Effects from usage of pre‑trip information and passenger scheduling strategies on waiting times in public transport: An empirical survey based on a dedicated smartphone application
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Ingår i: Public Transport. - 1613-7159. ; :Special Issue CASPT
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Tidskriftsartikel (refereegranskat)abstract
- Waiting times are important indicators of the degree of travel time optimisation andother behavioural traits among public transport (PT) passengers. As previous studieshave shown, the level and usage of pre-trip information regarding schedule or realtime departures are important factors that infuence the potential to realise traveltime savings by enabling PT passengers to optimise waiting times. Most empiricalevidence regarding the revealed PT travel behaviour concerning information levelsis based on manual interviews or traditional travel surveys, in which there is a riskthat the actual context of where and when the choice of departure time was madeis not taken into account. This paper reports the results of a travel survey based ona dedicated smartphone application applied in a feld study in a Swedish mid-sizeurban and regional context. Context-aware notifcation prompting was used to allowrespondents to state their use of pre-trip information as well as whether they hadpre-planned their trip and how contingent planning aids were used for time optimisation. The implications on passenger waiting times of the use of informationregarding departure times by passengers were emphasised during analyses of theresulting data, along with personal characteristics, in which auxiliary sources suchas timetable data and Automatic Vehicle Location were utilised to determine groundtruth trip trajectories and trip-contextual factors. The results indicate the signifcance of having access to pre-trip information, especially for long trips above onehour’s duration, in order to pre-plan and thereby optimise waiting times. In addition,the use and source of pre-trip information difer among age and gender groups. Trippurpose and time of day to some extent determine waiting times and choice of tripoptimisation strategy (arrival or departure time).
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| 5. |
- Berggren, Ulrik, et al.
(författare)
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Intrapersonal variability in public transport path choice due to changes in service reliability
- 2022
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Ingår i: Transportation. - : Springer Science and Business Media LLC. - 0049-4488 .- 1572-9435. ; 49:6, s. 1517-1547
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Tidskriftsartikel (refereegranskat)abstract
- Uncertainty during the course of a trip is regarded as a particularly disturbing phenomenon by public transport (PT) passengers and has been shown to have a substantial impact on travel behaviour. However, so far there has been little empirical evidence within contemporary research concerning the degree of mid- to long-term adaptation among PT passengers to changes in the principal cause of such uncertainty within PT transport systems: Lack of service departure reliability. While most studies to date have focussed on instantaneous or short-term behavioural responses, this paper presents results from a one-year panel dataset consisting of individuals’ trip itineraries derived from smart card transactions enriched by automatic vehicle location (AVL) data. We measured long-term line route usage and departure reliability, the latter in terms of headway regularity and schedule adherence, in two panel waves. Thus, we aimed for practical indicators that may be associated with specific line routes and origin–destination PT stop pairs used for recurring trips over time. Results from logistic regression indicate a consistent significant impact of changed headway regularity and punctuality change for line routes with relatively high departure frequency. However, there is a relative indifference to long-term reliability change by a significant share of individuals that have actual trade-offs between at least two line route options, possibly indicating satisficing behaviour among PT passengers. Implications on PT path choice forecasting and route planning are discussed.
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| 6. |
- Berggren, Ulrik, et al.
(författare)
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Public transport path choice estimation based on trip data from dedicated smartphone app survey
- 2022
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Ingår i: Transportmetrica A: Transport Science. - : Informa UK Limited. - 2324-9935 .- 2324-9943. ; 18:3, s. 1813-1846
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Tidskriftsartikel (refereegranskat)abstract
- Having access to realistic and empirically grounded passenger valuations of public transport trip components facilitate the undertaking of necessary trade-offs during planning of transport networks. Discrete choice estimation of path choice preferences is a practical way to obtain such preferences. This paper proposes a new take on the empirical foundation of path choice estimation based on revealed choices by introducing trip data for full activity-based ‘door-to-door’ public transport trips collected from a dedicated survey application for smartphones. Choice probabilities were modelled based on an explicitly generated choice set, where the public transport trip parts were generated using a branch-and-bound approach. Results in terms of estimated preferences are comparable to those based on conventional surveying methods and suggest significant premiums for paths involving public transport stops with an elevated level of passenger service as well as differences in preferences across population groups.
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| 8. |
- Blom Västberg, Oskar, 1987-
(författare)
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Five papers on large scale dynamic discrete choice models of transportation
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Travel demand models have long been used as tools by decision makers and researchers to analyse the effects of policies and infrastructure investments. The purpose of this thesis is to develop a travel demand model which is: sensitive to policies affecting timing of trips and time-space constraints; is consistent with microeconomics; and consistently treats the joint choice of the number of trips to perform during day as well as departure time, destination and mode for all trips. This is achieved using a dynamic discrete choice model (DDCM) of travel demand. The model further allows for a joint treatment of within-day travelling and between-day activity scheduling assuming that individuals are influenced by the past and considers the future when deciding what to do on a certain day.Paper I develops and provides estimation techniques for the daily component of the proposed travel demand model and present simulation results provides within sample validation of the model. Paper II extends the model to allow for correlation in preferences over the course of a day using a mixed-logit specification. Paper III introduces a day-to-day connection by using an infinite horizon DDCM. To allow for estimation of the combined model, Paper III develops conditions under which sequential estimation can be used to estimate very large scale DDCM models in situations where: the discrete state variable is partly latent but transitions are observed; the model repeatedly returns to a small set of states; and between these states there is no discounting, random error terms are i.i.d Gumble and transitions in the discrete state variable is deterministic given a decision.Paper IV develops a dynamic discrete continuous choice model for a household deciding on the number of cars to own, their fuel type and the yearly mileage for each car. It thus contributes to bridging the gap between discrete continuous choice models and DDCMs of car ownership.Infinite horizon DDCMs are commonly found in the literature and are used in, e.g., Paper III and IV in this thesis. It has been well established that the discount factor must be strictly less than one for such models to be well defined.Paper V show that it is possible to extend the framework to discount factors greater than one, allowing DDCM's to describe agents that: maximize the average utility per stage (when there is no discounting); value the future greater than the present and thus prefers improving sequences of outcomes implying that they take high costs early and reach a potential terminal state sooner than optimal.
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