Thesis (MEng)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: Peak mornmg traffic-flow data were obtained from video footage of three
representative freeway sections on the Nl and N2 westbound towards Cape Town.
Flow, speed, and density measurements were made from the footage with the aid of a
stopwatch.
Many researchers (2-12) have originated and developed models to describe the
relationships between traffic flow characteristics (speed, flow, and density) on
freeways. In this report, a number of these models have been investigated with data
obtained from South African freeways. The ability of each model to predict flow
parameters over the entire range of data was evaluated with the aid of statistical
methods. The tests were performed by regressing average speed vs. average density.
Flow-density and speed-flow relationships were derived through application of the
steady-state equation (2.6). In each case, a final model was chosen through visual
inspection that consisted of two separate curves, one for the uncongested flow regime
and one for the congested flow regime. Furthermore, speed-flow relationships were
examined for individual lanes and compared to relationships established for average
lanes. The models were also compared to models obtained from overseas studies
(1,16,19) as well as from studies done locally (17).
A secondary objective of this study is to investigate the performance of existing
freeway facilities through application of the relevant models to the traffic-flow data of
a particular facility. The current peak-morning performance of the N2 freeway section
is investigated in terms of travel-time and travel cost. The particular study section
consists of three lanes, the right hand lane being an HOY lane dedicated to taxis and
buses. Different hypothetical cases are investigated. The first hypothetical case is an
investigation into the traffic situation on the freeway section without the influence of
the HOY lane. The second hypothetical case investigates the traffic situation on the
section with perfect operation of the HOY lane. The current performance of the N2
section is compared to the performance of each of the hypothetical cases. / AFRIKAANSE OPSOMMING: Oggend-spits verkeersvloei data is verkry vanaf drie verteenwoordigende seksies op
die Nl en N2 deurpaaie naby Kaapstad met die gebruik van 'n video kamera. Vloei,
spoed, end digtheid opnames is gemaak met behulp van 'n stophorlosie.
Verskeie navorsers (2-12) het modelle gepostuleer en ontwikkelom die verhoudings
tussen verkeersvloei eienskappe (spoed, volume, en digtheid) op deurpaaie te beskryf.
In hierdie verslag word 'n aantal van hierdie modelle ondersoek met data wat verkry
is van Suid-Afrikaanse deurpaaie. Die vermoë van elke model om vloei eienskappe
oor die hele bestek van die data te voorspel is geëvalueer met behulp van statistiese
metodes. Statistiese toetse behels 'n regressie analise van gemiddelde spoed teenoor
gemiddelde digtheid. Volume-digtheid en spoed-volume verwantskappe is direk
afgelei vanaf Vergelyking 2.6. Vir elke geval is 'n finale model m.b.v. visuele
inspeksie gekies wat bestaan het uit twee afsonderlike kurwes, een kurwe vir die vryvloei
regime en 'n ander kurwe vir hoë-digtheid toestande. Verder word spoedvolume
verwantskappe vir afsonderlike deurpad-lane ondersoek en vergelyk met
verwantskappe wat verkry is vir gemiddelde lane. Die modelle word ook vergelyk met
modelle wat verkry is vanaf oorsese studies (1,16,19), sowel as met modelle wat
plaaslik verkry is (17).
'n Sekondêre doel van hierdie studie is om die prestasie van bestaande deurpadfasiliteite
te ondersoek deur die verskillende modelle aan te wend tot die verkeersvloei
data van 'n betrokke fasiliteit. Die prestasie van die N2 deurpad seksie
gedurende oggend-spits verkeer is ondersoek in terme van reistyd en ryskoste. Die
betrokke seksie bestaan uit drie lane, waarvan die regter laan gereserveer is vir busse
en taxis. Verskeie hipoteses is ook ondersoek. Die eerste hipotese is 'n ondersoek na
die verkeers-vloei kondisie op die seksie sonder die invloed van die bus- en taxi-laan.
Die tweede hipotese ondersoek die seksie met perfekte werking van die bus- en taxilaan.
Die huidige prestasie van die N2 seksie is vergelyk met die prestasie van elk van
die hipoteses.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/52261 |
| Date | 12 1900 |
| Creators | Roux, Jacques |
| Contributors | Bester, C. J., Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | 126 p. : ill. |
| Rights | Stellenbosch University |
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