The impact of the covid-19 pandemic on urban movement: using floating car data to analyse road-based traffic patterns

The COVID-19 pandemic significantly affected global day-to-day movement patterns. Travel demand was markedly reduced worldwide as a result of governmental directives to reduce the spread of the SARS-CoV-2 virus. The South African government implemented a stepwise lockdown approach according to five Alert Levels, which have guided movement, social gatherings, and economic activities throughout the pandemic. Variation in traffic congestion levels was obvious on urban roads in South African cities, linked to changing Alert Levels. The purpose of this paper is to investigate how the pandemic has impacted urban, road-based movement patterns, and to evaluate if mobility trends are tending towards a “new normal” or returning to pre-pandemic patterns. It is important, particularly for planning authorities, to understand the long-term impacts of the pandemic to know if the observed changes to congestion and trip distribution patterns will be ongoing, or if we can anticipate a general return to pre-pandemic movement patterns. A case study analysis of traffic movement patterns in Cape Town is conducted using traffic volume and commercial floating car data (FCD) to evaluate variation in congestion and trip distribution patterns throughout 2020 and 2021. Analysis revealed the severe impact that lockdown had on traffic and movement patterns. Furthermore, the study determined that while 2021 traffic volume and congestion remained somewhat lower than 2019 levels, trip distribution patterns had returned to a pre-lockdown profile by the end of 2021. This is the first detailed South African study of pandemic related urban movement pattern changes using FCD, also offering a case study into how commercial FCD behaves in Sub-Saharan Africa when evaluating the traffic impact of a significant event.Papers presented at the 40th International Southern African Transport Conference on 04 -08 July 202

Small-city traffic management using unmanned aerial vehicles (uavs)

Dedicated Traffic Management Centres (TMCs) are only operational in three of the largest metropolitan areas in South Africa (in Gauteng, eThekwini and Cape Town). Smaller cities and towns do not have TMCs to assist with traffic management due to the prohibitive cost of these facilities. This research considers the benefits that a small city environment could gain from live traffic management, specifically considering the town of Stellenbosch in the Western Cape as a case study. Stellenbosch experiences heavy congestion during the morning and afternoon peak periods due to significant trip attractions. A framework for the implementation of UAVs to monitor traffic as part of TMC activities was determined for Stellenbosch. A case study includes determination of flight parameters; flight height and speed, as well as the path a could UAV follows to monitor traffic in a 4 km radius around its point of deployment. A framework for the implementation of UAVs to incident response is also created, indicating how UAVs could be used to aid emergency response personnel to better understand and respond to an incident scene. The cost benefit of using UAVs compared to traditional CCTV monitoring for traffic management was evaluated. Additionally, the benefits and limitations of such a system are identified according to findings from the case study. It was determined that using UAVs could provide substantial benefits for traffic monitoring in small city environments.Papers presented virtually at the 39th International Southern African Transport Conference on 05 -07 July 202

Measuring the impact of roadworks on traffic progression using floating car data

Roadworks projects, while necessary to upgrade and maintain our transport networks, are loathed for their presumed negative impact on our daily commute. The purpose of this study is to investigate how Floating Car Data (FCD) can be used to assess the influence of a work zone on traffic progression. The effective change in speed and travel time was examined within and around a work zone of the recently completed upgrade of the N1 in Cape Town, particularly during the lane closure of the inbound section of the N1 between Durban Road and Jip de Jager Drive. The use of FCD to assess the impact of work zones provided unprecedented insight into traffic patterns such as the change in position of bottlenecks during roadworks. FCD was shown to improve our understanding of traffic movement within work zones. This can provide input to strategies for safer traffic accommodation during roadworks, going some way to improve the daily commute of road users.Papers presented virtually at the 39th International Southern African Transport Conference on 05 -07 July 202

Hubbard-U calculations for Cu from first-principles Wannier functions

We present first-principles calculations of optimally localized Wannier functions for Cu and use these for an ab-initio determination of Hubbard (Coulomb) matrix elements. We use a standard linearized muffin-tin orbital calculation in the atomic-sphere approximation (LMTO-ASA) to calculate Bloch functions, and from these determine maximally localized Wannier functions using a method proposed by Marzari and Vanderbilt. The resulting functions were highly localized, with greater than 89% of the norm of the function within the central site for the occupied Wannier states. Two methods for calculating Coulomb matrix elements from Wannier functions are presented and applied to fcc Cu. For the unscreened on-site Hubbard $U$ for the Cu 3d-bands we have obtained about 25eV. These results are also compared with results obtained from a constrained local-density approximation (LDA) calculation.Comment: 13 pages, 8 figures, 5 table

Micromobility : testing suitability through fcd to improve overall mobility

Papers presented virtually at the 41st International Southern African Transport Conference on 10-13 July 2061Micromobility refers to the use of small, lightweight, and often non-motorised vehicles for short trips and last-mile connections that can either by privately owned, or part of a transport offering through a fleet of vehicles owned by a mobility service provider. Micromobility solutions have the potential to significantly reduce congestion and improve the urban environment. This paper aims to investigate how floating car data (FCD) can be used to evaluate the opportunity for micromobility to unlock mobility solutions for both short trips (5 km to 10 km) and long trips (>10 km), to encourage more sustainable urban movement. This paper investigates micromobility options using the town of Stellenbosch as a case study. The potential role of micromobility is investigated by considering typical trip patterns in Stellenbosch, collected through commercial FCD detailing motorised trips. The option of creating linkages between micromobility and infrastructural elements such as vehicle parking areas and “park and ride” facilities to increase the reach of micromobility are also considered. The research revealed a high level of suitability of micromobility for internal trips made within Stellenbosch, and external trips heading into Stellenbosch from surrounds when coupled with infrastructure upgrades (“park and ride”) and ride-share facilities. The paper also demonstrates the benefits of FCD for micromobility planning

Spatially and temporally distinct patterns of expression for VPS10P domain receptors in human cerebral organoids

Vacuolar protein sorting 10 protein (VPS10P) domain receptors are a unique class of intracellular sorting receptors that emerge as major risk factors associated with psychiatric and neurodegenerative diseases, including bipolar disorders, autism, schizophrenia, as well as Alzheimer’s disease and frontotemporal dementia. Yet, the lack of suitable experimental models to study receptor functions in the human brain has hampered elucidation of receptor actions in brain disease. Here, we have adapted protocols using human cerebral organoids to the detailed characterization of VPS10P domain receptor expression during neural development and differentiation, including single-cell RNA sequencing. Our studies uncovered spatial and temporal patterns of expression unique to individual receptor species in the human brain. While SORL1 expression is abundant in stem cells and SORCS1 peaks in neural progenitors at onset of neurogenesis, SORT1 and SORCS2 show increasing expression with maturation of neuronal and non-neuronal cell types, arguing for distinct functions in development versus the adult brain. In neurons, subcellular localization also distinguishes between types of receptor species, either mainly localized to the cell soma (SORL1 and SORT1) or also to neuronal projections (SORCS1 and SORCS2), suggesting divergent functions in protein sorting between Golgi and the endo-lysosomal system or along axonal and dendritic tracks. Taken together, our findings provide an important resource on temporal, spatial, and subcellular patterns of VPS10P domain receptor expression in cerebral organoids for further elucidation of receptor (dys) functions causative of behavioral and cognitive defects of the human brain