Rethinking Wat’s Dyke: A Monument’s Flow in a Hydraulic Frontier Zone

Britain’s second-longest early medieval monument – Wat’s Dyke – was a component of an early medieval hydraulic frontier zone rather than primarily serving as a symbol of power, a fixed territorial border or a military stop-line. Wat’s Dyke was not only created to monitor and control mobility over land, but specifically did so through its careful and strategic placement by linking, blocking and overlooking a range of watercourses and wetlands. By creating simplified comparative topographical maps of the key fluvial intersections and interactions of Wat’s Dyke for the first time, this article shows how the monument should not be understood as a discrete human-made entity, but as part of a landscape of flow over land and water, manipulating and managing anthropogenic and natural elements. Understanding Wat’s Dyke as part of a hydraulic frontier zone not only enhances appreciation of its integrated military, territorial, socio-economic and ideological functionality and significance, most likely the construction of the middle Anglo-Saxon kingdom of Mercia, it also theorises Wat’s Dyke as built to constitute and maintain control both across and along its line, and operating on multiple scales. Wat’s Dyke was built to manage localised, middle-range as well as long-distance mobilities via land and water through western Britain and beyond.

Conditional Transit Signal Priority for Connected Transit Vehicles

Connected vehicle (CV) technologies enable safe and interoperable wireless communication among vehicles and the infrastructure with the possibility to run many applications that can improve safety, and enhance mobility. This paper develops CV-based algorithms which use transit vehicle speed and the estimated time that the vehicle needs to arrive at an intersection to trigger transit signal priority (TSP) initiation. This information is updated each second based on the traffic conditions such as speed, a current distance of a transit vehicle to the intersection, and queue conditions. The algorithm uses the actual speed of a transit vehicle and its latitude/longitude (lat/lon) coordinates to compute the time that the vehicle needs to reach the stop line. It was tested on a real-world network using VISSIM traffic simulation, but can easily be implemented in the field, since it is using world coordinates. The upgraded algorithm was applied to a future bus rapid transit (BRT) scenario, and included different levels of conditional TSP, which depend on three combined conditions: the time that a transit vehicle needs to reach the stop line, the number of passengers on board, and the lateness that the transit vehicle experiences. The test-case network used for model building is a corridor consisting of ten signalized intersections along State Street in Salt Lake City, UT. The CV algorithms coupled with TSP can yield notable delay reductions for both the regular bus and the BRT of 33% and 12%, respectively.

Hand Detection for Safety to Avoid Accidents

Detecting the hand when it crosses the safety level and in return it also raises an alert in the form of alarm. So that the threat can be identified and proper measures are taken to overcome that. The methodology of the project goes as follows, taking input from camera , Image processing to detect hand, Projecting a line using computer vision, Raising alarm when hand crosses this projected safety line. The real time data is taken from the camera as an input to the Image processing algorithm. Then this input is processed to find the hand in image in it and checks whether the hand is crossing that safety line. If that hand is crossing the safety line we can simply raise alarm. The applications of the project are to the Employees who are working at industry are pushing the material into shredder machine. But somehow while pushing these material into shredder machine the employees are pushing their hands itself in the flow of work and the hands of employees were cut in that cause. So from a certain distance from shredder machine input we project a imaginary line using computer vision, So that if any hand crossing that imaginary line which is for safety we will raise an alarm. In addition, we can also extend the applications, by just replacing hand with the Bike, we can detect the bike, which is crossing the staggered stop line, and we can punish or fine them. As a part of object detection we are using Single short multibox detector.

Comparative study on e-bikes’ decision-making behaviors under flashing green and green countdown

Green flash light (FG) and green countdown (GC) are the two most common signal formats applied in green-red transition that provides drivers additional alert before termination of green phase. Due to their importance and function in stop-pass decision-making process, proper use of them has become a critical issue to greatly improve the safety and efficiency of signalized intersections. Gradually e-bike riders have become more important commuters in China, however, the influence of FG or GC on them is not clear yet and need pay more attention to it. This study chooses two almost identical intersections to obtain highly accurate trajectory data of e-bike riders to study their decision-making behaviors under FG or GC. The e-bike riders’ behavior is classified into four categories and is to identify their stop-pass decision points using the acceleration trend. Two binary-logit models were built to predict the stop–pass decision behaviors for the different e-bike rider groups, explaining that the potential time to the stop-line is the dominant independent factor of the different behaviors of GC and FG. Furthermore empirical analysis of decision points indicated that GC provides the earlier stop-pass decision point and longer decision making duration on the one side while results in more complexity of decision making and greater risk of stop-line crossing than FG on the other side.

Assessing Drivers’ Compliance with Restrictive Yellow Traffic Lights in a Developing Country

Driving rules adopt permissive or restrictive policies concerning yellow light running (YLR). In a restrictive policy, vehicles behind the stop line are not allowed to enter the intersection on yellow no matter how close they are to the stop line. YLR policy affects driving risks, safety, and operation. There is limited knowledge about the restrictive policy and drivers’ compliance with this rule. Previous studies on YLR are limited in scope since they tended to use binary stop/go decision models without considering red light running decisions. This potentially results in the loss of information about drivers’ conformity to red signals. This paper examines whether drivers are only non-compliant with yellow lights or whether non-conformity to any prohibitive yellow/red signal emerges as a wider behavioral issue. This study develops regression choice models to predict drivers’ illegal yellow-light passing decisions in a developing country with a poor safety record and explores reasons for drivers’ non-compliance. The results obtained show that the restrictive policy is ineffective in relation to driver compliance, especially in cases where drivers’ non-conformity to any restrictive rule emerges as a behavioral issue of concern. Drivers make their stop/go decisions according to the time needed to cross the intersection, and they consider the yellow light as an opportunity for crossing. Yellow (red) light running rates were 101 (31) per 1,000 vehicles per hour (vph) for the restrictive policy, whereas these rates for the U.S.A., with a permissive policy, were at most 29 (6) per 1,000 vph.

Analysis of saturation flow on isolated lanes of controlled intersections with significant traffic intensity

The methods and results of the investigation of intervals between vehicles during queue dissipation before controlled intersections with the further determination of saturation flow are reviewed in this paper. Having reviewed existing methods of determining the saturation in traffic flows, those are determined which provide the most certain results in conditions of intensive movement and take into account quite a large number of impact factors. Such methods are based on experimental measurement of intervals between vehicles during their passage through the stop-line in different directions of the controlled intersection. For the completeness of the analysis of such intervals, such factors are considered additionally as traffic composition and use of lanes by directions. Objects of the research are controlled intersections on approaches to which the slope is absent, there is no pedestrian and cyclist movement during the performance of turn, and conflicting traffic flows and also public transport stops in the zone of the intersection. The transitional research result is the determination of the number of vehicles that pass the stop-line during the permissive signal and time intervals between them, and the final result is the oncoming of saturation period on the lanes of straight and turns movement depending on traffic flow composition.

Operational Optimization at Signalized Metering Roundabouts Using Cuckoo Search/Local Search Algorithm

A metering roundabout where traffic is controlled by traffic lights with phase times influenced by queue detector occupancy might be the solution to enhance performance when there are unbalanced traffic flows at roundabouts. There have, however, been minimal studies on how the distance of the queue detector from the stop line affects signal phase time durations and the queuing lengths. This research, therefore, seeks to develop a Cuckoo Search/Local search Algorithm using parameters such as arrival volumes, conflicting volumes, detector distance and phase time to investigate the relationship of signal setting, detector location and queuing formulations. Also, some additional statistical tests were performed for the fitness of the data. In order to conduct solid model validations, model output data was compared against the AIMSUN model. The results from the analyses demonstrated that the queue detector distance can affect phase time durations and vehicle queuing lengths on the controlling approach as well as queuing lengths on the metered approach. This study showed that, based on the study for the Old Belair Road roundabout in Adelaide, South Australia, the total queue length (controlling + metered) will be minimized when the detector is relocated at 209 meters from the roundabout stop line, giving longer phase green times and resulting in decreased intersection queuing lengths.