High precision data from household travel survey (HTS) is extremely important for the transportation research, traffic models and policy formulation. Traditional methods of data collection were imprecise because they relied on people’s memories of trip information, such as date and location, and the remainder data had to be obtained by certain supplemental tools. The traditional methods suffered from intensive labor, large time consumption, and unsatisfactory data precision. Recent research trends to employ smartphone apps to collect HTS data. In this study, there are two goals to be addressed. First, a smartphone app is developed to realize a smartphone-based method only for data collection. Second, the researcher evaluates whether this method can supply or replace the traditional tools of HTS. Based on this premise, the smartphone app, TravelSurvey, is specially developed and used for this study. TravelSurvey is currently compatible with iPhone 4 or higher and iPhone Operating System (iOS) 6 or higher, except iPhone 6 or iPhone 6 plus and iOS 8. To evaluate the feasibility, eight individuals are recruited to participate in a pilot HTS. Afterwards, seven of them are involved in a semi-structured interview. The interview is designed to collect interviewees’ feedback directly, so the interview mainly concerns the users’ experience of TravelSurvey. Generally, the feedback is positive. In this study, the pilot HTS data is successfully uploaded to the server by the participants, and the interviewees prefer this smartphone-based method. Therefore, as a new tool, the smartphone-based method feasibly supports a typical HTS for data collection.

In accordance with the main aim of the study, a widely accessible, modifiable tool was created for parties interested in maintaining the national electricity supply network and parties interested in informing policy on plug-in vehicle adoption schemes and recharging behaviour control. The Parry Tool enables the user to incorporate present limits to plug-in vehicle recharging demand scheduling as imposed by the state of present technology (no third party mechanism for monitoring and control of recharging), present human travel behaviour needs and existing patterns in electricity usage; into the investigation of the impacts of recharging demand impacts and the design of mitigation measures for deflecting (parrying) worst case scenarios. The second aim of the project was to demonstrate the application of the Parry Tool. The multidisciplinary/interdisciplinary information gathered by the Parry Tool was used to produce national demand profiles for plug-in vehicle recharging demand, calculated using socioeconomic and travel behaviour-estimated population sizes for plug-in eligible vehicles and vehicle usage patterns, which were added to existing national electricity demand for a chosen test week – this was the first scenario subsequently tested. The information gathered by the Parry Tool was then used to inform the design of two demand management methods for plug-in vehicle recharging: Recharging Regimes and weekly recharging load-shifting – these were the second and third scenarios subsequently tested. Unmitigated simultaneous recharging demand in scenario 1 (all vehicles assumed to recharge at home upon arrival home every day) severely exacerbated peak demand, raising it by 20% above the highest peak in existing demand for the year 2009 over half an hour from 58,554 MW to 70,012 MW – a challenge to the generation sector. This increased the difference between daily demand minima and maxima and made the new total demand have sharper peaks – a challenge for grid regulators. Recharging Regimes in scenario 2 split the estimated national plug-in vehicle populations into groups of different sizes that started recharging at different times of the day, with the word ‘regime’ being applied because the spread of start times changed over the course of the test week from workdays to weekend. This avoided exacerbation of the peak and reduced the difference between daily demand minima and maxima by raising minima, providing a load-levelling service. Scenario 3 embellished the Recharging Regimes with workday-to-weekend recharging load-shifting that therefore took better advantage of the often overlooked weekly pattern in existing demand (demand being higher on workdays than weekends), by allowing partial recharging of a segment of the plug-in vehicle population. Limited consideration of the impact of changing vehicle energy usage (for which distance travelled was assumed to proxy in this study) showed that the more vehicles used their batteries during the day, the better the levelling effect offered by Recharging Regimes. Greater utilisation of battery capacity each day, however, can also be assumed to lessen the potential for workday-to-weekend load levelling, because load-shifting depends upon vehicles being able to partially recharge or defer recharging to later days and still meet their travel needs plus keep a reserve State Of Charge (SOC) for emergency and other unplanned travel. Whilst altering vehicle energy usage did not change the finding that unmitigated simultaneous recharging exacerbated existing peak demand, it was noted that when limited mileage variation was considered this sharpened the profile of total demand – the rise and fall of the new peak far steeper than that of the original peak in existing demand. The Parry Tool combines a series of integrated methods, several of which are new contributions to the field that use UK data archives but may potentially be adapted by researchers looking at energy issues in other nations. It presents a novel fossil-fuel based justification for targeting road transport – acknowledging energy use of fossil fuel as the originator of many global and local problems, the importance of non-energy use of petroleum products and subsequent conflicts of interest for use, and a fossil fuel dependency based well-to-wheel assessment for UK road transport for the two energy pathways: electricity and petroleum products. It presents a method for the recalculation and ranking of top energy use/users using national energy use statistics that better highlights the importance of the electricity industry. It also presents the first publicly documented method for the direct consultation and extraction of vehicle-focused statistics from the people-focused National Travel Survey database, including a travel behaviour and household income-based assessment of plug-in vehicle eligibility, used to scale up to national estimates for battery electric and plug-in electric hybrid vehicle (BEV and PHEV) national population sizes. The work presented here is meant to allow the reader to perceive the potential benefits of using several resources in combination. It details the Parry Tool, a framework for doing so, and where necessary provides methods for data analysis to suit. It should however be noted that methods were kept as simple as possible so as to be easily followed by non-specialists and researchers entering the field from other disciplines. Methods are also predominantly data-exploratory in nature: strong conclusions therefore should not be drawn. Rather, the work here should be seen as a guideline for future work that may more rigorously study these combined topics and the impacts they may have upon plug-in vehicle ownership, usage behaviour, impacts of recharging upon the national network and the design of mitigation measures to cope with this new demand.

The Texas state gas tax has been 20.0 cents per gallon since 1991, and the federal gas tax has been 18.4 cents per gallon since 1993. The gas tax is not only stagnant, but depreciating in value due to inflation. Thus, damage is being done to the infrastructure but the money needed to maintain and improve roadways is not being adequately generated. One proposed alternative to the gas tax is the creation of a vehicle miles traveled (VMT) fee; with equity being a crucial issue to consider. This research used 2009 National Household Travel Survey (NHTS) Texas data to consider the equity impacts surrounding four VMT fee scenarios. Data were filtered and weighted to reflect results representative of Texas vehicle-owning households in 2008. Each scenario was run both statically and dynamically under the assumption that the VMT fee would replace the state gas tax. An assessment of the relative vertical equity of each scenario was made by calculating the Gini Coefficient associated with the proportion of state gas tax or VMT fee revenue generated by each household income level quintile. Results indicate that all VMT fee scenarios are essentially as equally vertically equitable than the current state gas tax system. Scenario 4 was designed to be inherently horizontally equitable because the per mile fee associated with each roadway type (urban or rural) was assessed to all vehicles driven on these roadway types at a rate calculated to generate needed funds to address the mobility and infrastructure needs of that roadway type. Scenario 3, a scenario favoring vehicles with high fuel efficiency, was found to be the least horizontally equitable. Scenarios 2-4 were able to generate additional revenue desired to meet the infrastructure and mobility needs of Texas set forth by the 2030 Texas Transportation Needs Committee. The large fee increase necessary to achieve the desired additional revenue may not be popular or possible. However, an evaluation of the philosophy governing each scenario designed to generate additional revenue is informative when it comes to equity impacts. No one VMT fee scenario affects all household income levels and geographic locations uniformly and it was not the goal of this research to design an equitable VMT fee scenario. Rather, the effect of each scenario on 2008 Texas vehicle-owning households disaggregated by household income level and geographic location are presented and left to the discretion of elected officials to decide which VMT fee, if any, would be best for their constituents.

With the emerging nationwide availability of plug-in electric vehicles (PEVs) at prices attainable for many consumers, electric utilities, system operators, and researchers have been investigating the impact of this new source of electricity demand. The presence of PEVs on the electric grid might offer benefits equivalent to dedicated utility-scale energy storage systems by leveraging vehicles' grid-connected energy storage through vehicle-to-grid (V2G) enabled infrastructure. Existing research, however, has not effectively examined the interactions between PEVs and the electric grid in a V2G system. To address these shortcomings in the literature, longitudinal vehicle travel data are first used to identify patterns in vehicle use. This analysis showed that vehicle use patterns are distinctly different between weekends and weekdays, seasonal interactions between vehicle charging, electric load, and wind generation might be important, and that vehicle charging might increase already high peak summer electric load in Texas. Subsequent simulations of PEV charging were performed, which revealed that unscheduled charging would increase summer peak load in Texas by approximately 1\%, and that uncertainty that arises from unscheduled charging would require only limited increases in frequency regulation procurements. To assess the market potential for the implementation of a V2G system that provides frequency regulation ancillary services, and might be able to provide financial incentives to participating PEV owners, a two-stage stochastic programming formulation of a V2G system operator was created. In addition to assessing the market potential for a V2G system, the model was also designed to determine the effect of the market power of the V2G system operator on prices for frequency regulation, the effect of uncertainty in real-time vehicle availability and state-of-charge on the aggregator's ability to provide regulation services, and the effect of different vehicle characteristics on revenues. Results from this model showed that the V2G system operator could generate revenue from participation in the frequency regulation market in Texas, even when subject to the uncertainty in real-time vehicle use. The model also showed that the V2G system operator would have a significant impact on prices, and thus as the number of PEVs participating in a V2G program in a given region increased, per-vehicle revenues, and thus compensation provided to vehicle owners, would decline dramatically. From these estimated payments to PEV owners, the decision to participate in a V2G program was analyzed. The balance between the estimated payments to PEV owners for participating in a V2G program and the increased probability of being left with a depleted battery as a result of V2G operations indicate that an owner of a range-limited battery electric vehicle (BEV) would probably not be a viable candidate for joining a V2G program, while a plug-in hybrid electric vehicle (PHEV) owner might find a V2G program worthwhile. Even for a PHEV owner, however, compensation for participating in a V2G program will provide limited incentive to join. / text

De flesta människor reser dagligen till arbete, skola eller för att uträtta ärenden, men dessvärre utgör sätten som vi reser på en belastning på miljön som inte är förenlig med en långsiktigt hållbar samhällsutveckling. I Sverige står transportsektorn för ungefär en fjärdedel av landets energianvändning och cirka 30 procent av landets totala klimatutsläpp. En stor del av utsläppen genereras av persontransporter och forskare menar att en minskad energianvändning genom ett smartare och mer hållbart resande är en viktig utveckling för att minska transportsektorns miljöpåverkan. Då arbetsrelaterade resor utgör hälften av alla persontransporter i Sverige, spelar företag en betydande roll, eftersom de har möjlighet att påverka både arbets- och tjänsteresor. Syftet med examensarbetet är att undersöka hur ett företag och arbetsplats, ÅF i Solna, kan skapa förutsättningar för hållbara arbets- och tjänsteresor. Vidare är syftet att ta fram åtgärdsförslag baserat på ÅF:s mål med att minska miljöpåverkan från resor. Mot bakgrund av utförda litteraturstudier, som redogör för bakgrunden till företags arbete för hållbara resor, som beskriver svenska arbetsmetoder för ändamålet och som diskuterar goda exempel på åtgärder som utförts av organisationer i Sverige, har en studie av platsförutsättningar och en resvaneundersökning genomförts på ÅF i Solna. Resultaten visar att tjänsteresor står för 73 procent av koldioxidutsläppen från resor och arbetsresor för 27 procent. Nästintill samtliga internationella tjänsteresor görs med flyg. Cirka 50 procent av alla nationella tjänsteresor görs med bil, 25 procent med flyg och 25 procent med tåg. Vid lokala tjänsteresor utgör bilresor ungefär 65 procent och kollektivtrafiksresor utgör cirka 30 procent. På ÅF i Solna görs ungefär 40 procent av arbetsresorna med bil, 40 procent med kollektivtrafik och 20 procent med gång, cykel och övriga färdsätt, sett över hela året. Studien visar att de anställda är intresserade av frågor som rör hållbart resande och efterfrågar satsningar på området. I studien konstateras att ÅF i Solna kan underlätta för hållbara arbets- och tjänsteresor genom att informera om hållbara resor och de möjligheter som redan finns på kontoret. Vidare kan ÅF utveckla och förbättra de befintliga förutsättningarna, genom att till exempel genomföra mindre fysiska åtgärder för att se över tillkortakommanden som kan utgöra hinder för förändrade resvanor. Dessutom kan ÅF i Solna utreda möjligheten att införa incitament som underlättar för hållbara resvanor och att arbeta med en grön resplan. / Most people travel to work, school or run errands on a daily basis, but the way that we travel constitute an environmental impact that is not consistent with a long term sustainable development. In Sweden the transport sector accounts for about a quarter of the country’s energy use and about 30 percent of its total carbon emissions. A large share of the emissions is generated by passenger transport and researchers argue that reduced energy usage by smarter and more sustainable travel is important to reduce the transport sector’s environmental impact. Since work related travel accounts for half of all Swedish passenger transport, companies play a significant role, as they can affect both journeys to work and business travel. The purpose of the degree project is to investigate how a company and a workplace, ÅF in Solna, can create conditions for sustainable commuting and business travel. The aim is further to develop action proposals based on ÅF’s goal to reduce its carbon footprint. On the basis of conducted literature studies, which explain the background of companies’ efforts towards sustainable travel, describe Swedish work methods and discuss good examples of undertaken measures by Swedish organisations, a study of site conditions and a travel survey is carried out at ÅF in Solna. The results show that business travel accounts for 73 percent of the carbon emissions from travel and commuting for 27 percent. Nearly all international business travel is made by flight. Approximately 50 percent of national business travel is made by car, 25 percent by flight and 25 percent by train. Cars account for about 65 percent of local business travel and public transport for about 30 percent. At ÅF in Solna approximately 40 percent of commuting is made by car, 40 percent by public transport and 20 percent by walk, bike and other modes of travel, for a full year. The study shows that employees are interested in issues related to sustainable travel and ask for commitments in the field. The study concludes that ÅF in Solna can facilitate sustainable commuting and business travel by providing information on sustainable travel and the opportunities that already exists at the office. Further, ÅF can develop and improve existing conditions, for example by carrying out minor physical measures to revise shortcomings that may prevent changing travel habits. Additionally, ÅF in Solna can investigate the possibility of introducing incentives that facilitate sustainable travel habits and working with a travel plan.

No description available.

The Stockholm Congestion Tax Trial is one of the few projects where an automatic system was implemented to tax road vehicles in order to reduce congestion. The taxation period lasted from January until July 2006 and vehicles going in or out of the inner city during daytime were taxed with 10 to 20 SEK (1.07 to 2.14 Euro). The project included improved public transportation and more park & ride sites. The trial was limited to a half year and the public was able to vote on the congestion tax afterwards. A large research package was set up in order to inform everybody about the effects of the tax. The referendum was positive and the congestion tax is permanent today, but the data collected for research purposes is not fully analyzed yet. This thesis focuses on travel behavior of the population in Stockholm County and uses a household panel survey with 24,000 individuals. The waves took place in September 2004 and March 2006.The main idea is to use the advantages of the panel survey and keep track of how the individuals behaved during the two waves. The analysis is done separately for each trip purpose and examines the change of mode choice during the second wave in comparison to the individual’s choice before the congestion tax. This can be even specified for different socio-demographic groups.The cross-sectional comparison shows that avoiding trips to and from the inner city is not an option. The number of trips of the individuals passing through the congestion tax cordon is reduced to a lower extend by seasonal influences than the trips in all other parts of the county. Therefore the inner city has become more attractive as a origin or destination or the trips passing through the cordon can not be substituted by trips free of tax.Public transportation is the mode which benefits most from the congestion tax in terms of modal split. The importance of it increases in the whole county, but the gain is a lot higher for trips through the cordon. The modes foot and bike are not a relevant alternative for trips through the cordon because of long distances in general and cold weather during the survey. The panel analysis shows that many more people doing cordon passages to work, home and shopping change from car to public transportation in comparison to the rest of the county. Changes from public transport to car occur less often for cordon passages than for trips not being taxed.Certain socio-demographic groups adapt differently to the congestion tax. Compared to men, up to 30 percent point fewer women continue to use the car depending on the trip purpose. This may be related to personal income, but the variables household income has proofed to have a smaller impact. Only really poor households use the car a lot less often and the highest income group tends to continue to drive by car.The main limiting factor of the analysis is the seasonal and weather influence because of unusual cold weather during the second wave. It is not possible to take this completely into account because the control group of the cordon passages has different trip characteristics.The thesis provides better knowledge how a congestion tax affects the behavior of the people. It allows checking the reasonability of transportation modeling results and shows that certain socio-demographic variables should be used if modeling is done for areas with a different composition of the population than Stockholm. / Der Versuch der Stockholmer Innenstadtmaut ist eines der wenigen Projekte, bei dem ein automatisches Mauterhebungssystem für Fahrzeuge zur Stauminderung eingeführt wurde. Der Versuchszeitraum mit Mauterhebung reichte von Januar bis Juli 2006. Alle Fahrzeuge, die in und aus der Innenstadt fuhren, mussten tagsüber 10 bis 20 SEK (1,07 bis 2,14 Euro) bezahlen. Das Projekt beinhaltete einen verbesserten öffentlichen Personennahverkehr und mehr Park&Ride-Stellplätze.Der Versuch war auf ein halbes Jahr begrenzt und im Anschluss wurde eine Volksabstimmung durchgeführt. Zur Information der Bevölkerung über die Auswirkungen der Maut wurde ein großes Forschungspaket aufgelegt. Die Volkabstimmung verlief positiv und die Maut ist heute dauerhaft eingeführt, aber die gesammelten Daten aus dem Forschungsprojekt sind noch nicht vollständig ausgewertet. Diese Arbeit konzentriert sich auf das Mobilitätsverhalten der Bevölkerung im Bezirk Stockholm und verwendet eine Panelbefragung in Haushalten mit 24.000 Teilnehmern. Die Befragungswellen fanden im September 2004 und März 2006 statt.Die Untersuchung verfolgt das Verhalten einzelner Individuen während der beiden Wellen und nutzt somit die Vorteile, die die Panelbefragung bietet. Die Analyse wird separat für jeden Wegezweck durchgeführt und betrachtet die Änderung der Verkehrmittelwahl während der zweiten Welle im Vergleich zur ursprünglichen Wahl vor der Maut. Dies wird durch die Auswertung einzelner soziodemographischer Gruppen ergänzt.Die Querschnittsuntersuchung zeigt, dass die Maut nicht zu einer Vermeidung von Wegen in oder aus der Innenstadt führt. Die Anzahl an Wegen durch den Mautgürtel nimmt leichter durch saisonale Einflüsse ab als in anderen Teilen des Bezirkes. Somit ist die Stadt entweder als Quell- oder Zielgebiet attraktiver geworden oder die Wege durch den Mautgürtel können nicht durch kostenfreie Fahrten ersetzt werden.Der öffentliche Personennahverkehr profitiert im Sinne vom Modal Split am meisten von der Maut. Die Bedeutung steigt im gesamten Bezirk, aber das Wachstum ist deutlich stärker für Wege durch den Mautgürtel. Die Verkehrsmittel Fuß und Fahrrad sind keine Alternative für die kostenpflichtigen Wege, da die Reiseweiten zu hoch sind und das Wetter zu kalt war. Die Panelanalyse zeigt, dass deutlich mehr Personen mit Wegen durch den Mautgürtel zur Arbeit, nach Hause und zum Einkaufen vom Auto zum öffentlichen Verkehr umsteigen als im Rest des Bezirks. Wechsel vom öffentlichen Verkehr zum Auto treten seltener bei Wegen in oder aus der Innenstadt auf als bei kostenfreien Fahrten.Einzelne soziodemographische Gruppen passen sich besonders an die Maut an. Frauen ersetzen je nach Wegezweck im Vergleich zu Männern bis zu 30 % häufiger das Auto durch alternative Verkehrsmittel. Dies kann mit geringerem persönlichen Einkommen zusammenhängen, aber die Variable Haushaltseinkommen hat in der Untersuchung einen eher geringen Einfluss bewiesen. Nur sehr arme Haushalte nutzen das Auto deutlich weniger und die Haushalte in der höchsten Einkommensgruppe behalten die Autonutzung bei.Die gesamte Analyse wird durch saisonale Einflüsse und das Wetter eingeschränkt, das während der zweiten Welle ungewöhnlich kalt war. Dieser Einfluss kann nicht vollständig berücksichtigt werden, da die Kontrollgruppe für die Wege durch den Mautgürtel Unterschiede bei der Wegecharakteristik aufweist.Die Studienarbeit verbessert das Wissen über Verhaltensänderungen der Menschen durch eine Maut. Sie ermöglicht die Überprüfung von Ergebnissen der Verkehrsmodellierung und zeigt, dass einzelne soziodemographische Merkmale für die Modellierung in anderen Regionen genutzt werden sollten, wenn die Zusammensetzung der Bevölkerung von Stockholm abweicht. / Stockholmsförsöket är ett av de få projekten som brukar ett automatik systemet för beskatta fordon med trängselskatt. Syftet är att minska trängseln på gatorna. Försöksperioden låg mellan januari och juli 2006. Fordon som åkte in eller ut i innerstaden måste betala 10 till 20 SEK under dagtid. Försöket omfattade förbättrad kollektivtrafik samt fler infartsparkeringar.Försöket var begränsat till ett halvt år och allmänhet hade folkomröstning om skatten senare. En stort  paket med många forskningsprojekt startas för att informera alla om effekter av skatt. Folkomröstning gav ett jakande svar och trängselskatt är idag permanent. Men all samlad data är ännu inte analyserad. Det här examensarbetet koncentrerar på resvanor av alla invånare i Stockholms Län och använder kohortstudier med 24 000 personer. Vågor uppstod i september 2004 och mars 2006.Huvudideen var att  använda sig av kohortstudier och studera beteendet i båda vågorna. Alla ärenden analyserades separat och skillnaderna på färdmedelna undersötes mellan förre och efter trängselskatt. Det kan även bli specificerad för flera olika sociala bakgrundsgrupper.Tvärsnittstudiens analys visar att förhindra resor till och från innerstaden inte är ett alternativ. Antal av resenärer som passerat avgiftssnittet har inte minskat så mycket av väder än alla andra resor i länet. Innerstaden är mer attraktiv som utgångspungt eller destination. De kan inte ersättnas med resor som kostar ingen skatt.Färdmedelfördelning har förbättrats för kollektivtrafiken på grund av trängselskatt. Kollektivtrafiken ökar i hela länet, men vinsten är störst för resor som passerat avgiftnittet. Färdmedeln fot och cykel är inget alternativ på grund av långt avstånd och dåligt väder under andra vågor. Kohortstudier visar att många resenärer byter från bil till kollektivtrafiken när man resan till jobbet, hemmet och inför shoping om man jämför med hela länet. Växling från kollektivtrafiken till bil är mindre för resorna som måste betala skatt.Några sociala grupper anpassar sig annorlunda till trängselskatten. Kvinnor åker bil ner till 30 procent mindre än men. Orsak är kanske lägre personlig inkomst, men variabel hushållinkomst har mindre effekt. Fattiga hushåll andvänder  bil mycket mindre än rika hushåll, som åker bil mycket mer.Huvudbegränsningen av analysen är årstiderna och vädret,, som tillexempel ovanlig kallt väder under andra vågoen. Man kan inte förklara hela effekten därför att kontrollgruppen av har olika egenskaper.Examensarbetet  bättre kunskap hur trängselskatten påverkar beteendet av människor. Det möjliggör att kontrollera transportmodellerings resultat och visar att några variabler skulle användas om modellering skulle göras i annan region med en annan typ av  sammansättning av befolkning  än i Stockholm.

Die vorliegende Dissertationsschrift geht der Frage nach, wie die Qualität von Haushaltsbefragungen zum Verkehrsverhalten bestimmt, bewertet und für zukünftige Erhebungen sichergestellt werden kann. Dabei spielt die Teilnahmebereitschaft als ein bedeutsamer, keinesfalls aber alleiniger Qualitätsindikator eine wichtige Rolle. Eine zentrale Forschungsfrage der Arbeit beschäftigt sich mit der Eignung gruppenspezifischer Ansprache und Befragung zur Erhöhung der Befragungsqualität. Ausgehend von grundsätzlichen Betrachtungen zu Bedeutung, wesentlichen Designelementen und insbesondere Fehlerquellen von Befragungen in der empirischen Sozialforschung, sind verschiedene Ansätze zur Einschätzung der Qualität einer Befragung Gegenstand dieses Teils der Arbeit. Darauf aufbauend werden stichtagsbezogene Haushaltsbefragungen zum Verkehrsverhalten im Alltag als Spezialfall von Befragungen eingeführt und Ansätze zur Qualitätssicherung bei derartigen Haushaltsbefragungen zusammengetragen. Eine Gegenüberstellung von Designelementen und möglichen Fehlern bei Verkehrsverhaltensbefragungen ermöglicht die Identifizierung und Beschreibung von neun Handlungsfeldern. Im Kontext von Erkenntnissen aus der Erhebungspraxis sowie Erfahrungen bei der Durchführung mehrerer Durchgänge des Forschungsprojektes „Mobilität in Städten – SrV“ wird eingeschätzt, inwieweit die jeweiligen Handlungsfelder zur Verminderung von Fehlereinflüssen und zur Qualitätssicherung beitragen können. Auf dieser Grundlage werden konkrete Handlungsoptionen ausgewählt. Für die Einschätzung der Handlungsoptionen hinsichtlich ihrer Wirksamkeit bei der Sicherung und Steigerung der Erhebungsqualität können auf Basis umfangreicher Literaturauswertungen insgesamt 24 Qualitätsindikatoren zusammengestellt werden. Diese ermöglichen die systematische Bewertung der Erfassungs-, Inhalts- und Durchführungsqualität. Unter Einbeziehung der Untersuchungsgruppen und Qualitätsindikatoren wird in einer vertieften empirischen Analyse untersucht, in welchem Maße die ausgewählten Handlungsoptionen zur gruppenspezifischen Ansprache und Befragung geeignet sind und ob sich dadurch die Erhebungsqualität steigern lässt. Neben umfangreichen Gruppenvergleichen findet eine Befragungssimulation nach der Monte-Carlo-Methode statt. Die Datenbasis dieser Analysen besteht überwiegend aus den Erhebungsdurchgängen und Sondererhebungen von „Mobilität in Städten – SrV“. Im Ergebnis der Analysen lassen sich Empfehlungen für die Weiterentwicklung von Haushaltsbefragungen zur Erfassung von Verkehrsverhaltensdaten ableiten. Diese gliedern sich in einen gruppenübergreifenden Teil und einen Abschnitt für spezielle Gruppen. Noch vorangestellt ist die klare Empfehlung, bei Haushaltsbefragungen zukünftig nur noch eine Person des Haushalts zu ihren Wegen am Stichtag zu befragen. Dieses Vorgehen erleichtert die zukünftige Implementierung (sogar trennscharfer) gruppenspezifischer Ansätze deutlich. Die zusammengestellten Empfehlungen bieten eine konsistente, praktikable und auf andere Befragungen übertragbare Basis, das Erhebungsdesign bestehender und zukünftiger Haushaltsbefragungen zum Verkehrsverhalten so anzupassen, dass durch die vollständige oder zumindest teilweise Umsetzung gruppenspezifischer Ansätze eine Verbesserung der Erhebungsqualität insgesamt erzielt werden kann. / This dissertation addresses the question of how the quality of household travel surveys can be determined, evaluated, and ensured for the development of future surveys. The willingness of individuals to participate is an important, but by no means exclusive, indicator of quality. A central research question of this work deals with the concept of combining group-specific survey methods to increase survey quality. Beginning with some fundamental terminological considerations, this work then focuses on essential design elements and, in particular, sources of error in surveys in empirical social research in order to establish various approaches for assessing the quality of a survey. Building on this, household travel surveys are introduced in specific examples, and approaches for quality assurance in such household travel surveys are compiled. A comparison of design elements and possible errors in household travel surveys provides for the identification and description of nine areas of activity. In the context of findings from the surveying practice as well as experience in conducting several waves of the research project "Mobility in Cities – SrV", the extent to which the respective fields of action can contribute to the reduction of errors and to quality assurance was assessed. On this basis, concrete options for action were selected. In order to evaluate the courses for action in terms of their effectiveness in securing and increasing the quality of surveys, a total of 24 quality indicators were compiled on the basis of extensive literature review. These allowed for the systematic assessment of three areas: quality of collection, content, and of application. With the involvement of analysis groups and quality indicators, a detailed empirical analysis was carried out to examine the extent to which the selected courses for action are suitable for group-specific combinations of survey methods and whether this can increase survey quality. In addition to extensive group comparisons, a survey simulation was implemented using the Monte Carlo method. The data foundation for these analyses primarily consisted of the surveys carried out for the research project "Mobility in Cities – SrV". These analyses enabled the establishment of recommendations which further the development of household travel surveys; these were divided into a cross-group section as well as a section for specific groups. Prior to these recommendations, it became clear that for future household travel surveys, only one individual in the household should be questioned regarding their trips on specific reference days. This decision significantly facilitates the future implementation of (even more selective) group-specific approaches. The compiled recommendations provide a consistent, practical foundation that can be applied to other surveys in order to adapt the design of existing and future household travel surveys, thus providing an overall or at least partial implementation of group-specific approaches which can improve overall survey quality.

Die vorliegende Dissertationsschrift geht der Frage nach, wie die Qualität von Haushaltsbefragungen zum Verkehrsverhalten bestimmt, bewertet und für zukünftige Erhebungen sichergestellt werden kann. Dabei spielt die Teilnahmebereitschaft als ein bedeutsamer, keinesfalls aber alleiniger Qualitätsindikator eine wichtige Rolle. Eine zentrale Forschungsfrage der Arbeit beschäftigt sich mit der Eignung gruppenspezifischer Ansprache und Befragung zur Erhöhung der Befragungsqualität. Ausgehend von grundsätzlichen Betrachtungen zu Bedeutung, wesentlichen Designelementen und insbesondere Fehlerquellen von Befragungen in der empirischen Sozialforschung, sind verschiedene Ansätze zur Einschätzung der Qualität einer Befragung Gegenstand dieses Teils der Arbeit. Darauf aufbauend werden stichtagsbezogene Haushaltsbefragungen zum Verkehrsverhalten im Alltag als Spezialfall von Befragungen eingeführt und Ansätze zur Qualitätssicherung bei derartigen Haushaltsbefragungen zusammengetragen. Eine Gegenüberstellung von Designelementen und möglichen Fehlern bei Verkehrsverhaltensbefragungen ermöglicht die Identifizierung und Beschreibung von neun Handlungsfeldern. Im Kontext von Erkenntnissen aus der Erhebungspraxis sowie Erfahrungen bei der Durchführung mehrerer Durchgänge des Forschungsprojektes „Mobilität in Städten – SrV“ wird eingeschätzt, inwieweit die jeweiligen Handlungsfelder zur Verminderung von Fehlereinflüssen und zur Qualitätssicherung beitragen können. Auf dieser Grundlage werden konkrete Handlungsoptionen ausgewählt. Für die Einschätzung der Handlungsoptionen hinsichtlich ihrer Wirksamkeit bei der Sicherung und Steigerung der Erhebungsqualität können auf Basis umfangreicher Literaturauswertungen insgesamt 24 Qualitätsindikatoren zusammengestellt werden. Diese ermöglichen die systematische Bewertung der Erfassungs-, Inhalts- und Durchführungsqualität. Unter Einbeziehung der Untersuchungsgruppen und Qualitätsindikatoren wird in einer vertieften empirischen Analyse untersucht, in welchem Maße die ausgewählten Handlungsoptionen zur gruppenspezifischen Ansprache und Befragung geeignet sind und ob sich dadurch die Erhebungsqualität steigern lässt. Neben umfangreichen Gruppenvergleichen findet eine Befragungssimulation nach der Monte-Carlo-Methode statt. Die Datenbasis dieser Analysen besteht überwiegend aus den Erhebungsdurchgängen und Sondererhebungen von „Mobilität in Städten – SrV“. Im Ergebnis der Analysen lassen sich Empfehlungen für die Weiterentwicklung von Haushaltsbefragungen zur Erfassung von Verkehrsverhaltensdaten ableiten. Diese gliedern sich in einen gruppenübergreifenden Teil und einen Abschnitt für spezielle Gruppen. Noch vorangestellt ist die klare Empfehlung, bei Haushaltsbefragungen zukünftig nur noch eine Person des Haushalts zu ihren Wegen am Stichtag zu befragen. Dieses Vorgehen erleichtert die zukünftige Implementierung (sogar trennscharfer) gruppenspezifischer Ansätze deutlich. Die zusammengestellten Empfehlungen bieten eine konsistente, praktikable und auf andere Befragungen übertragbare Basis, das Erhebungsdesign bestehender und zukünftiger Haushaltsbefragungen zum Verkehrsverhalten so anzupassen, dass durch die vollständige oder zumindest teilweise Umsetzung gruppenspezifischer Ansätze eine Verbesserung der Erhebungsqualität insgesamt erzielt werden kann. / This dissertation addresses the question of how the quality of household travel surveys can be determined, evaluated, and ensured for the development of future surveys. The willingness of individuals to participate is an important, but by no means exclusive, indicator of quality. A central research question of this work deals with the concept of combining group-specific survey methods to increase survey quality. Beginning with some fundamental terminological considerations, this work then focuses on essential design elements and, in particular, sources of error in surveys in empirical social research in order to establish various approaches for assessing the quality of a survey. Building on this, household travel surveys are introduced in specific examples, and approaches for quality assurance in such household travel surveys are compiled. A comparison of design elements and possible errors in household travel surveys provides for the identification and description of nine areas of activity. In the context of findings from the surveying practice as well as experience in conducting several waves of the research project 'Mobility in Cities – SrV', the extent to which the respective fields of action can contribute to the reduction of errors and to quality assurance was assessed. On this basis, concrete options for action were selected. In order to evaluate the courses for action in terms of their effectiveness in securing and increasing the quality of surveys, a total of 24 quality indicators were compiled on the basis of extensive literature review. These allowed for the systematic assessment of three areas: quality of collection, content, and of application. With the involvement of analysis groups and quality indicators, a detailed empirical analysis was carried out to examine the extent to which the selected courses for action are suitable for group-specific combinations of survey methods and whether this can increase survey quality. In addition to extensive group comparisons, a survey simulation was implemented using the Monte Carlo method. The data foundation for these analyses primarily consisted of the surveys carried out for the research project 'Mobility in Cities – SrV'. These analyses enabled the establishment of recommendations which further the development of household travel surveys; these were divided into a cross-group section as well as a section for specific groups. Prior to these recommendations, it became clear that for future household travel surveys, only one individual in the household should be questioned regarding their trips on specific reference days. This decision significantly facilitates the future implementation of (even more selective) group-specific approaches. The compiled recommendations provide a consistent, practical foundation that can be applied to other surveys in order to adapt the design of existing and future household travel surveys, thus providing an overall or at least partial implementation of group-specific approaches which can improve overall survey quality.

The quest towards resolving concerns about transportation energy consumption and emissions across nations has created more interests to investigate factors responsible for households’ car ownership. While literature holds an extensive body of investigation usually compartmentalised in individual different disciplines, limited efforts have been made to promote inter-linkages of this strand of research across different disciplines. To fill this gap, this study developed an integrating Multinomial logit (MNL) model to examine the impact of some rarely-investigated and conventional explanatory variables, including: ethnicity, accommodation tenure, settlement nature, mental belief, environmental concern, geographical regions, household structure, driving licence, number of household income earners and household income, on car ownership. Analysis based on rich data sets of British Household Survey and US Consumer Expenditure Survey found not only the conventional explanatory variables to be significantly linked to the number of cars in the US and UK households, but also the rarely-investigated psychological variables were found to be significantly linked as well. As Socio-demography, Geography and Psychology impact on how people and households process information and assess market offers (e.g., products and services), this study presents findings which have beneficial implications for policymakers and transportations planners, including those who would like to alter people’s behaviour from private car ownership to public transportation use, car sellers in terms of how to identify and reach potential customers, provision of alternative forecasting approaches to car ownership scholars as well as possible consideration for general car ownership decision making. Caution should be taken when interpreting the relationship between psychological factors and car ownership since the psychological factors adopted are measure representatives from databases used with limitations in the factor structure for a representative sample of the countries’ population.