Restricting freight traffic in urban areas: The economic and traffic impact of banning heavy vehicle movement in Stellenbosch during peak periods

Date
2019-04
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: Whenever new traffic regulations are proposed for implementation, it is crucial to investigate the effects that they will have on the operations of the transportation network. In this study, the potential impact of heavy vehicle restrictions in urban areas, as proposed by the South African Department of Transportation in 2015, was investigated. No evidence could be found to indicate that there had been any research performed into the effects of such restrictions before, or since, this proposal was made. Therefore, this study aimed to fill this gap. Although the regulations were proposed in an attempt to improve road safety, the focus of this study lies on the potential impact of the regulations on traffic conditions and the economy. Two main areas of research were addressed in this study; the first being the investigation of the current heavy vehicle movement patterns in Stellenbosch, and the second being the assessment of the impact of heavy vehicle bans on the traffic operations on the town’s road network. It was determined that almost no research had been performed in the past regarding the movements of freight vehicles in Stellenbosch and, therefore, this study aimed to fill this gap. Fleet management data from MiX Telematics and vehicle movement surveys were analysed for this purpose. From the analysis of fleet management data, the temporal and spatial distribution patterns of freight vehicles in Stellenbosch were determined. It was found that the majority of freight vehicles in Stellenbosch travel during the day and that the R44 and Bird Street are two of the most used roads for freight trips. The vehicle movement surveys found that the majority of freight trips in the town originate locally or in nearby towns. The potential impact of heavy vehicle bans on traffic conditions were investigated with the use of a microscopic traffic model constructed in PTV Vissim. The model examined the potential effects of the proposed bans on the transportation network of Stellenbosch in both the cases that latent demand was present in the town and the case where it was not. It was found that traffic conditions generally improved when latent demand was not present, but it worsened when latent demand was present. Even when traffic conditions improved, the changes were small, with no traffic condition improving by more than 10%. A high-level economic evaluation was performed in order to determine the economic impact of the proposed bans. It was found that passenger car drivers would experience economic losses if latent demand were present in Stellenbosch. In the absence of latent demand, passenger car drivers have the potential of saving R23 109.81 during the six banning hours, but it is believed that these benefits would be far outweighed by the cost of implementation of the bans and the losses experienced by the freight industry. The proposed heavy vehicle restrictions were not deemed feasible for implementation and more research would have to be performed into the effects of the bans on a national level.
AFRIKAANSE OPSOMMING: Wanneer nuwe verkeersregulasies voorgestel word vir implementasie, is dit hoogs noodsaaklik om die effekte daarvan op die werking van die verkeernetwerk te ondersoek. In hierdie studie word die potensiële impak van swaar voertuig beperkings in stadsgebiede, soos voorgestel deur die Suid-Afrikaanse Departement van Vervoer in 2015, ondersoek. Geen bewyse kon gevind word wat aangedui het dat enige navorsing na die effekte van sulke beperkings uitgevoer is voor, of sedert, dit voorgestel is nie. Daarom het hierdie studie gemik om die gaping te vul. Alhoewel die regulasies voorgestel is in ʼn poging om padveiligheid te verbeter, lê die fokus van hierdie studie op die potensiële impak wat die regulasies op verkeer en die ekonomie kan hê. Twee hoof areas van navorsing is aangespreek in hierdie studie; die eerste daarvan is die ondersoek na die huidige swaar voertuig bewegingspatrone in Stellenbosch en die tweede is die assessering van die impak van swaar voertuig beperkings in die dorp se padnetwerk. Dit is vasgestel dat daar amper geen navorsing in die verlede gedoen is oor die bewegings van vragvoertuie in Stellenbosch nie en daarom mik hierdie studie om die gaping te vul. Vloot bestuur data van MiX Telematics en voertuig bewegingsopnames is geanaliseer vir hierdie doeleinde. Deur die analise van vloot bestuur data is die temporale en ruimtelike verspreidingspatrone van vragvoertuie in Stellenbosch vasgestel. Dit is gevind dat die meerderheid van vragvoertuie in Stellenbosch gedurende die dag reis en dat die R44 en Bird Straat twee van die mees benutte paaie vir vrag-ritte is. Die voertuig bewegingsopnames het bevind dat die meerderheid van vrag-ritte in die dorp plaaslik of in nabye dorpe ontstaan. Die potensiële impak van swaar voertuig beperkings op verkeerkondisies is ondersoek deur die gebruik van ʼn mikroskopiese verkeersmodel, gebou in PTV Vissim. Die model is gebruik om te ondersoek wat die effekte van die voorgestelde verbannings sou wees op die verkeerkondisies in Stellenbosch in beide die gevalle dat daar latente aanvraag in die dorp teenwoordig was en die geval waar dit nie was nie. Dit is bevind dat verkeerkondisies oor die algemeen verbeter het wanneer latente aanvraag nie teenwoordig was nie, maar dat dit vererger het wanneer latente aanvraag wel teenwoordig was. Selfs wanneer verkeerkondisies verbeter het, was die verandering klein, met geen verkeerkondisie wat met meer as 10% verbeter het nie. A hoë-vlak ekonomiese evaluasie is uitgevoer om die ekonomiese impak van die voorgestelde verbannings vas te stel. Dit is bevind dat passasiersvoertuig bestuurders ekonomiese nadele sou ondervind indien daar latente aanvraag teenwoordig was in Stellenbosch. Indien geen latente aanvraag teenwoordig was nie, kon passasiersvoertuig bestuurders die potensiaal hê om R23 109.81 te bespaar gedurende die ses verbanningsure, maar dit is geglo dat hierdie voordele baie kleiner is as die koste van implementasie van die verbannings en die verliese wat deur die vrag industrie gedra sal word. Die voorgestelde swaar voertuig beperkings is nie voordelig geag vir implementasie nie en meer navorsing sal uitgevoer moet word na die effekte wat die verbannings op ʼn nasionale vlak sal hê.
Description
Thesis (MEng)--Stellenbosch University, 2019.
Keywords
Transportation engineering, Freight transportation, Urban areas, Traffic engineering, UCTD
Citation