Morning peak period travel characteristics of a residential suburb in Cape Town during a school and holiday period : what lessons can we learn?

Hermant, Laurent Fernand Leon (2008-03)

Thesis (MScEng)--University of Stellenbosch, 2008.

Thesis

ENGLISH ABSTRACT: It is argued that an understanding of variability is central to the modelling of travel behaviour and the assessment of policy impacts and is not the peripheral issue that it has often been considered. There is a growing need to assess multi-day data to assess the distribution of user charges for road pricing, or patterns of public transport usage as well as improve the ability to identify mechanisms behind travel behaviour for modelling purposes. Drawing on studies worldwide, in conjunction with a review of the literature, the thesis first examines the relevance for using multi-day data, then discusses the methodology and results of a five week survey undertaken specifically for this study, makes a comparison of the findings with that observed in other studies, and finally discusses issues relating to the application of the data and future research possibilities. Previous studies have shown that behaviour which makes up the daily travel pattern can be highly repetitious in nature but that observing an individual’s behaviour on a single day might not be representative of their routine travel and that this behaviour varies across demographic segments and driver gender. This paper examines day-to-day travel behaviour variability of a residential area, Summer Greens, located in Cape Town (South Africa) using a travel dataset collected recently in November/December 2006. The survey technique employed was the recording of numberplates of all exiting vehicles from 06:00 to 10:00, weekdays from Monday to Friday over a period of five weeks. A total of 5677 vehicles undergoing 44 743 trips was observed and analysed. This research replicates and extends previous work dealing with day-to-day variability in trip-making behaviour that was conducted with data collected by Del Mistro and Behrens (2006) in Buitengracht Street, Cape Town CBD, in July/August 2005. The present research extends the earlier work by including departure time variations as well as conducting the observations during both a school period (3 weeks) and consecutive holiday period (2 weeks). Further, the thesis presents a method to measure day-to-day variability using the available data surveyed. This thesis finds a considerable difference in school and holiday traffic volumes as expected, but that despite this, certain identical travel behaviour patterns (such as vehicle appearance frequencies, following week repeat proportions etc.) is observed during both these periods. It was found that the peak hour for both school and holiday periods occurred during the same time period and greater traffic volume variability was found to occur on Fridays during the holiday period than in the school period. Traffic volumes across all weeks appeared to decrease from Monday to Wednesday and “bounce back” on Thursday and Friday consistent with the findings of another international study. It was found that motorists exhibited more departure time freedom during the holiday period with average holiday departure times much later than during the school period. Departure times were also observed to gradually become later from Monday to Friday during both the school and holiday periods with Thursday and Friday departure times significantly different to the other weekdays. The proportion of unique vehicles observed was found to increase with time of day and the resulting impact of this on the effectiveness of Variable Message Sign (VMS) applications is also discussed. The research concludes by applying the findings to determine the impact of a hypothetical congestion pricing scheme on traffic volumes.

AFRIKAANSE OPSOMMING: Die argument is dat ‘n begrip vir variasie sentraal staan tot die modellering van reisgedrag en die assessering van beleidsimiplikasies, en is dus nie net n nagedagte soos wat gereeld gedink word nie. Daar is ‘n toenemende behoefte om multi-dag data te analiseer om die verspreiding in gebruikerskostes te bestudeer vir die waardasie van paaie, of om verhoudings in publieke vervoergebruik uit te lig, asook, vir die verbetering van die vermoë om die meganismes agter reisgedrag te identifiseer vir modelleringsdoeleindes. Die tesis bestudeer eerstens die relevansie van die gebruik van multi-dag data in samewerking met die literatuurstudie, gebaseer op studies wêreldwyd onderneem. Tweedens bespreek dit die metodologieë en resultate van ‘n vyf-week lange opname wat spesifiek vir hierdie studie onderneem is en tref vergelykings met die resultate verkry deur vorige studies. Dit bespreek dan die probleme wat voortspruit uit die toepassing van die data en ook toekomstige moontlikhede tot verdere navorsing. Vorige studies het getoon dat die gedrag wat tydens daaglikse reispatrone voorkom van nature hoogs herhaaldelik is. Wanneer ‘n individu se gedrag observeer word op ‘n enkele dag is dit egter nie noodwendig verteenwoordigend van sy/haar roetine reisgedrag nie en dat hierdie gedrag afhanklik is van demografiese faktore en die geslag van die bestuurder. Hierdie tesis bespreek die variasie in dag-tot-dag reisgedrag van ‘n residensiële gebied, Summer Greens, in Kaapstad (RSA) deur gebruik te maak van ‘n datastel wat onlangs saamgestel is (November/Desember 2006). Die data is ingesamel deur ‘n opname te doen van die nommerplate van alle uitgaande voertuie tussen 06:00 en 10:00, weeksdae van Maandag tot Vrydag, oor ‘n periode van vyf weke. A totale aantal voertuie van 5677 wat 44 743 ritte onderneem het, is waargeneem en ‘n analise is uitgevoer. Die navorsing herhaal en brei uit op vorige werk wat die dag-tot-dag variasie in ritopwekking bestudeer. Del Mistro en Behrens (2006) het data bestudeer wat ingesamel is in Julie/Augustus 2005 in Buitengrachtstraat, in die Kaapse Middestad (RSA). Die huidige navorsing brei uit op hierdie werk deur die variasie in vertrektyd in te sluit asook om waarnemings te doen tydens die skoolperiode (3 weke) en die daaropvolgende vakansieperiode (2 weke). ‘n Metode word ook aangebied om die dag-tot-dag variasie te meet deur middel van die beskikbare data wat ingesamel is. Hierdie tesis vind ‘n merkwaardige verskil in die skool en vakansie verkeersvolumes, soos verwag kan word, maar ten spyte daarvan bestaan daar sekere identiese reisgedragspatrone (byvoorbeeld die frekwensies waarteen ‘n voertuig voorkom, weeklikse herhaling van proporsies, ens.) gedurende beide hierdie periodes. Die bevinding is dat die spitsuur vir skool- en vakansieperiodes gedurende dieselfde tydsperiode plaasvind en dat verkeersvolumes groter variasie toon op Vrydae gedurende die vakansieperiode, as die skoolperiode. Dit wil blyk of verkeersvolumes gedurende al die weke afneem van Maandag tot Woensdag en dan “terug spring” op Donderdae en Vrydae. Hierdie bevinding is in ooreenstemming met resultate van ‘n ander internasionale studie. Motoriste het ‘n neiging getoon tot groter vryheid in terme van vertrektye tydens die vakansieperiode, met die gemiddelde vakansie vertrektye heelwat later as gedurende die skoolperiode. Vertrektye is ook gevind om geleidelik later te word van Maandag tot Vrydag gedurende beide die skool en vakansieperiodes, met Donderdag en Vrydag se vertrektye wat merkwaardig verskil van ander weeksdae. Die verhouding uniek waargenome voertuie het volgens hierdie navorsing se bevindinge toegeneem met die tyd van die dag en die gevolglike impak hiervan op die effektiwiteit van sogenaamde “Vehicle Message Sign” toepassings word bespreek. Die navorsing sluit dan af deur die bevindinge toe te pas om die impak te bepaal wat ‘n hipotetiese kongestieprysskema op verkeersvolumes het.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/20443
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