A proof of concept investigating the support of densification through the planning and implementation of road infrastructure in the South African context

Govender, Kerisha (2020-03)

Thesis (MEng)--Stellenbosch University, 2020.

Thesis

ENGLISH ABSTRACT: In recent decades, the metropolitan areas of Johannesburg and Pretoria in South Africa have expanded rapidly. It is expected that the trend will continue in the future. Planning and implementation of road infrastructure, controlling urban sprawl, compact city layouts, jobs-housing balance, mobility in around urban areas and the viability and efficiency of public transport systems within and around regions have been an ongoing concern for transportation planners. These elements are inter-dependent and form the principles in creating a compact city. With ongoing refinements, they can eventually be the key to achieving “The Future City”. The “Future City” concept, currently being developed in Europe (for example Barcelona Superblocks) enshrines the concept of “live, work and play” in areas within proximity of each other. Although urban design paradigms are shifting, it is argued that approaches to strategic transportation planning can facilitate the Future City by ensuring shorter trip lengths, higher gross-population densities in cities and efficient public transport systems are achieved. The aim of this study is to develop a proof of concept to investigate the support of densification through the planning and implementation of road infrastructure in the South African context. A linking idea to this concept tests the question of “Are we spending our road infrastructure budget correctly?”. The main outcomes of this study are: • A set of synthesized deterrence functions for trips on the Gauteng Freeway Improvement Project (GFIP) road network; • Graphical representations of congestion on the GFIP road infrastructure resulting from the assignment of the different synthesized deterrence functions; • Resulting trip lengths and trip times from the assignment of each synthesized deterrence function to the GFIP network; and • Economic Benefit/Disbenefit in terms of travel time for the base year and design year per scenario tested. The objective of this study is to demonstrate that shorter trips and densification can be supported through the planning and implementation of road infrastructure, which can in turn promote the viability of the Future Cities concept. The research methodology estimates the deterrence function for the existing trip distribution on the GFIP network and uses that function to develop synthesized deterrence functions to test various trip distribution scenarios. Synthesized trip matrices, produced from each synthesized deterrence function, were assigned to the GFIP road network to obtain comparable trip lengths, travel times and congestion levels. All transport modelling was completed using the Simulation and Assignment of Traffic in Urban Road Networks (SATURN) software. A brief economic study relating to the economic benefit/disbenefit in terms of travel time was completed for each scenario to determine the optimal solution. The results from this study demonstrate that intelligent planning of road infrastructure can achieve the following: • Reduced urban sprawl; • Altered driver behaviour in terms of route choice and trip lengths; • Better managed regional expansion; • Increased residential density and mixed-use areas which are supported by an efficient public transport system; • Smaller road infrastructure budgets; and • An improved social experience of urban living. The study has resonance for all cities where urban sprawl is seemingly unstoppable.

AFRIKAANSE OPSOMMING: In Suid-Afrika, het die metropolitaanse gebiede van Johannesburg en Pretoria vinnig gegroei oor die afgelope dekades. Na verwagting sal hierdie neiging voortduur in die toekoms. Die beplanning en implementering van padinfrastruktuur, gekontrolleerde stedelike verspreiding, kompakte stedelike uitlegte, balans tussen werkgeleenthede en behuising, mobiliteit in stedelike gebiede en die lewensvatbaarheid en doeltreffendheid van openbare vervoerstelsels in en rondom streke, is 'n deurlopende bekommernis vir vervoerbeplanners. Hierdie elemente is onderling afhanklik en vorm die beginsels vir die skepping van kompakte stede. Die voortdurende verfyning van hierdie elemente, kan uiteindelik lei tot die sleutel vir die bewerkstelling van “The Future City”. Die "Future City" konsep, wat tans in Europa ontwikkel word (byvoorbeeld Barcelona Superblocks), omskryf die konsep van "live, work and play" in gebiede wat naby mekaar geleë is. Alhoewel stedelike ontwerpparadigmas verander, word dit aangevoer dat benaderings tot strategiese vervoerbeplanning die “Future City” kan ondersteun deur korter reislengtes, hoër bruto bevolkingsdigthede in stede en doeltreffende openbare vervoerstelsels te verseker. Die doel van hierdie studie is om 'n bewys van konsep te ontwikkel tot die ondersteuning van verdigting deur die beplanning en implementering van padinfrastruktuur in die Suid-Afrikaanse konteks te ondersoek. Die skakelidee van hierdie konsep toets die vraag: "Bestee ons, ons padinfrastruktuurbegroting optimaal?". Die kern uitkomstes van hierdie studie sluit in: • 'n Stel gesintetiseerde afskrikfunksies vir reise op die “Gauteng Freeway Improvement Project (GFIP)” padnetwerk; • Grafiese voorstellings van opeenhoping op die GFIP padinfrastruktuur as gevolg van die toewysing van die verskillende gesintetiseerde afskrikfunksies; • Resulterende reislengtes en reistye vanaf die toewysing van elke gesintetiseerde afskrikfunksie aan die GFIP netwerk; en • Ekonomiese voordeel / nadeel ten opsigte van die reistyd vir die basisjaar en die ontwerpjaar per toets. Die doel van hierdie studie is om aan te toon dat korter reistye en stedelike verdigting ondersteun kan word deur die beplanning en implementering van padinfrastruktuur, wat op sy beurt die lewensvatbaarheid van die “Future Cities” konsep kan bevorder. Die navorsingsmetodologie bepaal die afskrikfunksie vir die bestaande reisverspreiding op die GFIP netwerk en gebruik die funksie om gesintetiseerde afskrikfunksies te ontwikkel om verskillende reisverspreidingscenarios te toets. Gesintetiseerde ritmatrikse, ontwikkel uit elke gesintetiseerde afskrikfunksie, is aan die GFIP padnetwerk toegeken om vergelykbare reislengtes, reistye en opeenhopingsvlakke te bepaal. Alle vervoermodellering is uitgevoer met behulp van “Simulation and Assignment of Traffic in Urban Road Networks (SATURN)” sagteware. 'n Ekonomiese studie, rakende die ekonomiese voordeel / nadeel ten opsigte van reistye, is vir elke scenario uitgevoer om die optimale oplossing te bepaal. Die resultate van hierdie studie toon dat intelligente beplanning van padinfrastruktuur die volgende kan bereik: • Vermindering in stedelike verspreiding; • Verandering in bestuurdergedrag ten opsigte van roete keuse en reislengte; • Verbetering in streeksuitbreiding bestuur; • Verhoogde woondigtheid en gemengde gebruiksareas wat ondersteun word deur 'n doeltreffende openbare vervoerstelsel; • Kleiner padinfrastruktuurbegrotings; en • 'n Verbeterde sosiale ervaring van stedelike lewe. Die studie sal aanklank vind tot stede waar stedelike verspreiding oënskynlik onstuitbaar is.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/107777
This item appears in the following collections: