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Publications (10 of 17) Show all publications
Sprei, F., Habibi, S., Englund, C., Pettersson, S., Voronov, A. & Wedlin, J. (2019). Free-floating car-sharing electrification and mode displacement: Travel time and usage patterns from 12 cities in Europe and the United States. Transportation Research Part D: Transport and Environment, 71, 127-140
Open this publication in new window or tab >>Free-floating car-sharing electrification and mode displacement: Travel time and usage patterns from 12 cities in Europe and the United States
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2019 (English)In: Transportation Research Part D: Transport and Environment, ISSN 1361-9209, E-ISSN 1879-2340, Vol. 71, p. 127-140Article in journal (Refereed) Published
Abstract [en]

Free-floating car-sharing (FFCS) allows users to book a vehicle through their phone, use it and return it anywhere within a designated area in the city. FFCS has the potential to contribute to a transition to low-carbon mobility if the vehicles are electric, and if the usage does not displace active travel or public transport use. The aim of this paper is to study what travel time and usage patterns of the vehicles among the early adopters of the service reveal about these two issues. We base our analysis on a dataset containing rentals from 2014 to 2017, for 12 cities in Europe and the United States. For seven of these cities, we have collected travel times for equivalent trips with walking, biking, public transport and private car. FFCS services are mainly used for shorter trips with a median rental time of 27 min and actual driving time closer to 15 min. When comparing FFCS with other transport modes, we find that rental times are generally shorter than the equivalent walking time but longer than cycling. For public transport, the picture is mixed: for some trips there is no major time gain from taking FFCS, for others it could be up to 30 min. For electric FFCS vehicles rental time is shorter and the number of rentals per car and day are slightly fewer compared to conventional vehicles. Still, evidence from cities with an only electric fleet show that these services can be electrified and reach high levels of utilization.

Keywords
Alternative trips, Electric vehicles, Free-floating car-sharing, Shared mobility, Travel time, Usage patterns, Vehicles, Floating car, Low carbon, Mode-displacements, Public transport, Time gain, Transport modes
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-36926 (URN)10.1016/j.trd.2018.12.018 (DOI)2-s2.0-85058802098 (Scopus ID)
Available from: 2018-12-28 Created: 2018-12-28 Last updated: 2019-06-28Bibliographically approved
Ploeg, J., Semsar-Kazerooni, E., Morales Medina, A., de Jongh, J. F., van de Sluis, J., Voronov, A., . . . van de Wouw, N. (2018). Cooperative Automated Maneuvering at the 2016 Grand Cooperative Driving Challenge. IEEE transactions on intelligent transportation systems (Print), 19(4), 1213-1226
Open this publication in new window or tab >>Cooperative Automated Maneuvering at the 2016 Grand Cooperative Driving Challenge
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2018 (English)In: IEEE transactions on intelligent transportation systems (Print), ISSN 1524-9050, E-ISSN 1558-0016, Vol. 19, no 4, p. 1213-1226Article in journal (Refereed) Published
Abstract [en]

Cooperative adaptive cruise control and platooning are well- known applications in the field of cooperative automated driving. However, extension toward maneuvering is desired to accommodate common highway maneuvers, such as merging, and to enable urban applications. To this end, a layered control architecture is adopted. In this architecture, the tactical layer hosts the interaction protocols, describing the wireless information exchange to initiate the vehicle maneuvers, supported by a novel wireless message set, whereas the operational layer involves the vehicle controllers to realize the desired maneuvers. This hierarchical approach was the basis for the Grand Cooperative Driving Challenge (GCDC), which was held in May 2016 in The Netherlands. The GCDC provided the opportunity for participating teams to cooperatively execute a highway lane-reduction scenario and an urban intersection-crossing scenario. The GCDC was set up as a competition and, hence, also involving assessment of the teams' individual performance in a cooperative setting. As a result, the hierarchical architecture proved to be a viable approach, whereas the GCDC appeared to be an effective instrument to advance the field of cooperative automated driving.

Keywords
Merging, Road transportation, Protocols, Wireless communication, Automation, Trajectory, Safety, adaptive control, cooperative communication, mobile robots, motion control, multi-robot systems, protocols, road safety, road traffic control, road vehicles, traffic engineering computing, vehicular ad hoc networks, velocity control, Cooperative driving, interaction protocol, controller design, vehicle platoons, wireless communications
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-33814 (URN)10.1109/TITS.2017.2765669 (DOI)2-s2.0-85035089916 (Scopus ID)
Available from: 2018-05-04 Created: 2018-05-04 Last updated: 2019-06-17Bibliographically approved
Ploeg, J., Englund, C., Nijmeijer, H., Semsar-Kazerooni, E., Shladover, S. E., Voronov, A. & Van de Wouw, N. (2018). Guest Editorial Introduction to the Special Issue on the 2016 Grand Cooperative Driving Challenge. IEEE transactions on intelligent transportation systems (Print), 19(4), 1208-1212
Open this publication in new window or tab >>Guest Editorial Introduction to the Special Issue on the 2016 Grand Cooperative Driving Challenge
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2018 (English)In: IEEE transactions on intelligent transportation systems (Print), ISSN 1524-9050, E-ISSN 1558-0016, Vol. 19, no 4, p. 1208-1212Article in journal, Editorial material (Refereed) Published
Abstract [en]

Cooperative driving is based on wireless communications between vehicles and between vehicles and roadside infrastructure, aiming for increased traffic flow and traffic safety, while decreasing fuel consumption and emissions. To support and accelerate the introduction of cooperative vehicles in everyday traffic, in 2011, nine international teams joined the Grand Cooperative Driving Challenge (GCDC). The challenge was to perform platooning, in which vehicles drive in road trains with short intervehicle distances. The results were reported in a Special Issue of IEEE Transactions on Intelligent Transportation Systems, published in September 2012 [item 1 in the Appendix].

Keywords
Wireless communication, Cooperative systems, Automation, Systems architecture, Safety, Control systems
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-33816 (URN)10.1109/TITS.2018.2815103 (DOI)2-s2.0-85045020434 (Scopus ID)
Available from: 2018-05-04 Created: 2018-05-04 Last updated: 2019-06-17Bibliographically approved
Englund, C., Engdahl, H., Habibi, S., Pettersson, S., Sprei, F., Voronov, A. & Wedlin, J. (2018). Method for prediction of Utilization Rate of Electric Vehicle Free-Floating Car Sharing Services using Data Mining. In: : . Paper presented at 31st International Electric Vehicles Symposium & Exhibition (EVS 31) & International Electric Vehicle Technology Conference 2018 (EVTeC 2018), 2018.
Open this publication in new window or tab >>Method for prediction of Utilization Rate of Electric Vehicle Free-Floating Car Sharing Services using Data Mining
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2018 (English)Conference paper, Published paper (Other academic)
Abstract [en]

Free-floating car sharing is a form of car rental used by people for short periods of time where the cars can be picked up and returned anywhere within a given area. In this paper, we have collected free-floating car sharing data, for electric as well as fossil fueled cars, and data regarding e.g. size of the city, number of cars in the service, etc. The utilization rates of the free-floating car sharing services vary much between the cities, greatly influencing the success of the services. This paper presents the most important factors influencing the utilization rate, and also a methodology to predict the utilization rate for new cities, using data mining based on Random Forests.

National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-37617 (URN)
Conference
31st International Electric Vehicles Symposium & Exhibition (EVS 31) & International Electric Vehicle Technology Conference 2018 (EVTeC 2018), 2018
Available from: 2019-01-28 Created: 2019-01-28 Last updated: 2019-06-17Bibliographically approved
Habibi, S., Sprei, F., Englund, C., Voronov, A., Pettersson, S., Wedlin, J. & Engdahl, H. (2018). Success and Usage Pattern of Free-Floating Carsharing Services in Cities. In: : . Paper presented at Transportation Research Board 97th Annual Meeting Location: Washington DC, United States Date: 2018-1-7 to 2018-1-11.
Open this publication in new window or tab >>Success and Usage Pattern of Free-Floating Carsharing Services in Cities
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2018 (English)Conference paper, Published paper (Other academic)
Abstract [en]

Free-floating car sharing services (FFCS) have been offered as a more flexible mobility solution than other car sharing services. FFCS users can pick up and return cars anywhere within a specified area in a city.The objective of this paper is to identify similar usage patterns of FFCS in different cities as well as city characteristics that make these services a viable option. The authors have access to real booking data for 32 cities in Europe and North America. Their study shows the share of daily car trips is negatively correlated to the utilization rate of these services. Also, the higher the congestion and the harder finding a parking lot, the lower the utilization rate of these services is in the cities. Moreover, our results suggest that FFCS services do not compete with public transport but are rather used in combination to it. These services are mainly used during midday and evening peak and the trips taken by these services are mainly chained trips.The clustering analysis shows that the trips are grouped into two or three clusters in different cities. The majority of clusters are the inner city clusters which contain a significantly higher number of trips than the clusters around other points of interest such as airports.

National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-37614 (URN)
Conference
Transportation Research Board 97th Annual Meeting Location: Washington DC, United States Date: 2018-1-7 to 2018-1-11
Note

This paper was sponsored by TRB committee ADB10 Standing Committee on Traveler Behavior and Values.

Available from: 2019-01-28 Created: 2019-01-28 Last updated: 2019-06-17Bibliographically approved
Sprei, F., Englund, C., Habibi, S., Pettersson, S., Voronov, A., Wedlin, J. & Engdahl, H. (2017). Comparing electric vehicles and fossil driven vehicles in free-floating car sharing services. In: : . Paper presented at 5th European Battery, Hybrid and Fuel Cell Electric Vehicle Congress, 14-16 March, 2017, Geneva, Switzerland.
Open this publication in new window or tab >>Comparing electric vehicles and fossil driven vehicles in free-floating car sharing services
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2017 (English)Conference paper, Published paper (Refereed)
Abstract [en]

In recent years, free-floating car sharing (FFCS) services have been offered as a more flexible option compared to traditional car sharing. FFCS allows users to pick up and return cars anywhere within a specified area of a city. These can be either electric or fossil driven vehicles. We analyze the difference in usage of these two types of vehicles. The analysis is based on a dataset consisting of vehicle availability data sampled between 2014 and 2016 for 9 cities with EVs in the FFCS fleet. We find that there is no statistical difference in how EVs and fossil driven FFCS vehicles are used. When it comes to charging of EVs two main strategies are identified: widespread “slow charging” versus tailored fast-charging.

National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:ri:diva-33103 (URN)
Conference
5th European Battery, Hybrid and Fuel Cell Electric Vehicle Congress, 14-16 March, 2017, Geneva, Switzerland
Available from: 2018-01-16 Created: 2018-01-16 Last updated: 2019-06-17Bibliographically approved
Habibi, S., Sprei, F., Englund, C., Pettersson, S., Voronov, A., Wedlin, J. & Engdahl, H. (2017). Comparison of free-floating car sharing services incities. In: : . Paper presented at ECEEE 2017 Summer study. eceee 2017 Summer Study on energy efficiency Consumption, efficiency and limits ISSN: 2001-7960 (online)/1653-7025 (print) ISBN: 978-91-983878-1-0 (online)/978-91-983878-0-3 (print). , Article ID 4-109-17.
Open this publication in new window or tab >>Comparison of free-floating car sharing services incities
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2017 (English)Conference paper, Published paper (Refereed)
Abstract [en]

In recent years, free-floating car sharing services (FFCS) have been offered by many organizations as a moreflexible option compared to traditional car sharing. FFCS allows users to pick up and return cars anywherewithin a specified area of a city. FFCS can provide a high degree of utilization of vehicles and less usage ofinfrastructure in the form of parking lots and roads and thus has the potential to increase the efficiency of thetransport sector. However, there is also a concern that these compete with other efficient modes of transport suchas biking and public transport. The aim of this paper is to better understand how, when and where the vehiclesare utilized through logged data of the vehicles movements. We have access to data collected on FFCS servicesin 22 cities in Europe and North America which allows us to compare the usage pattern in different cities andexamine whether or not there are similar trends. In this paper, we use the collected data to compare the differentcities based on utilization rate, length of trip and time of day that the trip is made. We find that the vehicleutilization rates differ between cities with Madrid and Hamburg having some of the highest utilization levels forthe FFCS vehicles. The result form a first step of a better understanding on how these services are being usedand can provide valuable input to local policy makers as well as future studies such as simulation models.

National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:ri:diva-33077 (URN)
Conference
ECEEE 2017 Summer study. eceee 2017 Summer Study on energy efficiency Consumption, efficiency and limits ISSN: 2001-7960 (online)/1653-7025 (print) ISBN: 978-91-983878-1-0 (online)/978-91-983878-0-3 (print)
Note

Funding for this study is provided from the Swedish Energy Agency, Chalmers Area of Advance Transport andChalmers Area of Advance Energy.

Available from: 2018-01-15 Created: 2018-01-15 Last updated: 2019-06-17Bibliographically approved
Engdahl, H., Englund, C., Habibi, S., Pettersson, S., Sprei, F., Voronov, A. & Wedlin, J. (2017). Statistical Data for Free-floating Car Sharing versusPublic Transport. In: : . Paper presented at 30th International Electric Vehicle Symposium and Exhibition, EVS 2017; Landesmesse StuttgartStuttgart; Germany; 9 October 2017 through 11 October 2017.
Open this publication in new window or tab >>Statistical Data for Free-floating Car Sharing versusPublic Transport
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2017 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Free-floating car sharing is a form of car rental used by people for short periods of time where the cars canbe picked up and returned anywhere within a given area. In this paper, we have collected free-floating carsharing data, for electric as well as fossil fueled cars, and data for alternative trips using cycling, walking andpublic transport for the cities of Amsterdam, Berlin, Denver, Madrid, San Diego and Seattle. From this data,free-floating car sharing seems to be a compliment to other type of transports, including public transports,bicycling and walking, and not a competitor.

Keywords
: Car-sharing, EV (electric vehicle), public transport, data acquisition, city traffic
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:ri:diva-33089 (URN)2-s2.0-85050157832 (Scopus ID)
Conference
30th International Electric Vehicle Symposium and Exhibition, EVS 2017; Landesmesse StuttgartStuttgart; Germany; 9 October 2017 through 11 October 2017
Available from: 2018-01-15 Created: 2018-01-15 Last updated: 2019-08-14Bibliographically approved
Voronov, A., Hultén, J., Wedlin, J. & Englund, C. (2016). Radar reflecting pavement markers for vehicle automation. In: : . Paper presented at AstaZero Researchers Day - Emerging Trends in Active Safety for Road Vehicles, May 10, 2016, Borås, Sweden. Trafikverket
Open this publication in new window or tab >>Radar reflecting pavement markers for vehicle automation
2016 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Dependable and fail-safe control of autonomous vehicles requires multiple independent sensors for lane detection and positioning. From analysis of modern sensing technologies, we conclude that radars are underutilized for positioning, and that they might be an enabling technology for achieving safety requirements posed by the standard ISO 26262. To fully utilize the radar potential, we have conducted a pre-study of equipping infrastructure with radar reflectors. We estimate that such reflectors should be installed in the lane markings, about 20-25 meters apart and with some kind of identification. We propose to design and evaluate a combi-reflector based on the traditional cat’s eye design, which will be detectable both by human drivers, radars and lidars. Furthermore, the combi-reflector can be equipped with a magnet for in-vehicle electromagnetic field sensor. From the redundancy evaluation performed, we conclude that the proposed solution increases the level of redundancy significantly. Therefore, the proposed solution could be an enabler for autonomous driving. 

Place, publisher, year, edition, pages
Trafikverket, 2016
National Category
Computer and Information Science
Identifiers
urn:nbn:se:ri:diva-25412 (URN)10.13140/RG.2.1.1695.8323 (DOI)
Conference
AstaZero Researchers Day - Emerging Trends in Active Safety for Road Vehicles, May 10, 2016, Borås, Sweden
Projects
Radarreflektorer
Available from: 2018-03-28 Created: 2016-10-31 Last updated: 2019-06-25Bibliographically approved
Englund, C., Nilsson, M. & Voronov, A. (2016). The application of data mining techniques to model visual distraction of bicyclists. Expert systems with applications, 52, 99-107
Open this publication in new window or tab >>The application of data mining techniques to model visual distraction of bicyclists
2016 (English)In: Expert systems with applications, ISSN 0957-4174, E-ISSN 1873-6793, Vol. 52, p. 99-107Article in journal (Refereed) Published
Abstract [en]

This paper presents a novel approach to modelling visual distraction of bicyclists. A unique bicycle simulator equipped with sensors capable of capturing the behaviour of the bicyclist is presented. While cycling two similar scenario routes, once while simultaneously interacting with an electronic device and once without any electronic device, statistics of the measured speed, head movements, steering angle and bicycle road position along with questionnaire data are captured. These variables are used to model the self-assessed distraction level of the bicyclist. Data mining techniques based on random forests, support vector machines and neural networks are evaluated for the modelling task. Out of the total 71 measured variables a variable selection procedure based on random forests is able to select a fraction of those and consequently improving the modelling performance. By combining the random forest-based variable selection and support vector machine-based modelling technique the best overall performance is achieved. The method shows that with a few observable variables it is possible to use machine learning to model, and thus predict, the distraction level of a bicyclist.

Keywords
Automated driving systems, Bicycle simulator, Bicyclist distraction, Data mining, Random forest, Support vector machine
National Category
Signal Processing
Identifiers
urn:nbn:se:ri:diva-27848 (URN)10.1016/j.eswa.2016.01.006 (DOI)
Available from: 2017-01-11 Created: 2017-01-11 Last updated: 2019-06-19Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-0709-4954

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