## 3 Analysis of Bibliographic Results on Road Network Pricing
### Co-Citation Analysis
#### 3.4.4 Technology for Electronic Road Pricing Schemes  
The fast pace of developments in ERP technologies has enabled deployment of a number of automated schemes around the world [97]. In particular, the automation has allowed for free-flow charging without the need to stop and pay charges. These technologies comprise three key components including automated vehicle identification systems used to determine the identity of the vehicle and track its movement along the road network to be able to apply the correct charges [24]. Most systems today use radio-frequency identification based on gantry communication with vehicle transponders through dedicated short range communications (DSRC) [98]. The use of automatic number plate recognition (ANPR) is also common for vehicle identification [18]. The advantage of ANPR is that it avoids the need for in-vehicle devices, but it suffers from high error rates under severe weather conditions [98]. ERP technologies also include automated vehicle classification to classify different types of vehicles, including laser profilers that identify shapes of different vehicles and distinguish vehicle types for ease of charging. The ERP systems also include transaction processing and violation enforcement systems comprising back-office technologies that maintain customer accounts and issue infringement notices as needed. ANPR systems are typically used to capture images of vehicles where a transponder was missing or when the user's account did not have a sufficient balance. Singapore's congestion pricing used DSRC technology for communication between gantries and in-vehicle devices [54], while London and Stockholm relied on ANPR. In the German heavy goods vehicle charge scheme, digital tachyographs and smart cards were used to calculate the distance [99]. For distance-based road pricing, GPS is typically used for vehicle tracking and has been reported to be reliable [100]. The accuracy of the technologies varies with weather conditions, device resolution, and signal quality. Modern DSRC systems have an accuracy of 99 percent but suffer from inclement weather or when vehicle number plates cannot be read. Satellite systems can deliver wider coverage, but they suffer from resolution/accuracy issues compared to other technologies [100]. Microwave-based systems have also been found to be accurate for vehicle recognition [18]. Re-Imaging Urban Transport Amid and Post COVID-19: The Role of Road Pricing in Shaping a Resilient Urban Future  
The coronavirus pandemic has had a significant impact on cities all over the world. Building on the momentum of the shift to more sustainable practices will be one of the many challenges of recovery--and transportation will be a particular challenge. The pandemic, in particular, has shown how vulnerable public transport can be in the face of extreme stresses. As people try to maintain physical distancing and avoid crowded areas, public transport patronage has suffered and may continue to suffer for the next few years until the pandemic is contained. Thousands of journeys will have to be completed by other means every day. Congestion on the roads will worsen if people abandon public transportation in favour of driving. According to recent data, this may have already begun in major cities around the world, with recovery of public transportation trips lagging behind recovery of private vehicle trips. An example is shown in Figure 8 for Sydney, Australia, which shows that driving has already bounced back and has now exceeded the baseline traffic conditions of January 2020, while public transport and walking have both lagged behind in recovery This situation is not unique to Sydney and is being experienced by many cities around the world. There is considerable agreement in the literature that congestion will increase and persist if driving becomes a new habit, and many cities would risk losing on the past momentum and achievements in shifting travellers away from private vehicles.