DISSECTING THE SAFETY BENEFITS OF PROTECTED INTERSECTION DESIGN FEATURES

Protected intersections are an integral component of Complete Street networks and are used to facilitate and delineate the route cyclists should take while traveling along a protected network. The separation from the travel lane of automobiles, however, causes a decrease in driver attentiveness to cyclists. Rates of incidents of cyclists, specifically with right turning vehicles, have increased in recent years, leading to a desire to improve the safety benefits of existing protected intersections to increase the visibility of cyclists and driver awareness. This research used a simulated environment to test the effectiveness of different pavement markings and intersection radii on the speed and attentiveness of drivers. Participants were recruited to drive twelve scenarios in a simulated world and their speed, position, braking behavior, and glance pattern were analyzed to determine what combination of variables leads to the highest increase of safe interactions between cyclists and automobiles in a protected intersection. A speed and regression analysis were conducted to determine which variables influenced participants speeds the greatest, thereby improving the level of safety in the intersection. It was found that the size of the protected elements, the presence of a cyclist, and a participant’s gender were all significant in influencing the speed at which drivers navigated the intersection (p\u3c0.05) for right turns. The slowest speeds were recorded when a larger intersection radius was used in conjunction with a dashed white line through the protected intersection, suggesting that the combination of those two variables are effective in improving the level of safety for cyclists and motorists in a protected intersection

Cyclist Safety in Urban Areas

Cycling as an alternative means of transport is encouraged in urban areas because of the societal and environmental benefits it brings to most cities. However, the conflicts between cyclists and motorists become more obvious in complex urban areas, which places cyclists in a dangerous situation- a higher chance to get involved in serious injuries. To analyze how the problem happens, this paper talks about the user research, environment and collisions analysis. Then, this paper presents survey procedure and results related to user demands for cycling safety. The visibility limitation was found to be the main reason for the conflicts. In terms of solutions, this paper introduces theoretical methods and existing products suggested to enhance cyclists’ visibility, and it proposes a visibility system which is designed with the consideration of Maslow\u27s hierarchy of needs. The whole system makes cyclists conspicuous so as to reduce the collisions between cyclists and motorists

Optimization of signal-timing parameters for the intersection with hook turns

A Hook Turn (HT) traffic control scheme has been successfully implemented in urban Melbourne (Australia) ever since 1950s, for the regulation of right-turning vehicles at the intersections (in traffic system where driving is on the left). This paper addresses the optimal signal-timing of the HT scheme, which is still an open question in the literature. Under the HT scheme, right-turning vehicles should enter the intersection and stop at a waiting area. Hence, it is common to have a spillback from these vehicles if the right-turning volume is high. This paper provides an in-depth analysis of the spillback phenomenon on the traffic movements and the average delays, and proposes the models for the calculation of average delay in different cases. With the aim of minimizing the average delay of all the vehicles, a nonlinear integer-programming model is proposed for the optimal signal-timing problem of HT scheme. A Genetic Algorithm (GA) is used to solve this model, considering the complexity of its objective function. A realistic example developed based on one intersection with HT in urban Melbourne is adopted to assess the proposed methodology. Based on real survey data in morning peak and nonpeak hours, we compare the existing signal plan and optimal plan. The numerical test shows that compared with the existing plan, the optimal plan can reduce the average delay for 12.05% in peak hour and 19.96% in nonpeak hour. Sensitive analysis is also conducted to investigate the variation of right-turning ratio on the intersection operational performance

ASSESSING THE IMPACT OF BICYCLE TREATMENTS ON BICYCLE SAFETY: A MULTI-METHODS APPROACH

Compared to other modes, bicyclists are disproportionally affected by crashes considering their low mode share. There is evidence that crashes between bicyclists and motorized vehicle take place at road segments and signalized intersections where bicycle treatments (e.g., bike lanes) are present, urging for in-dept analysis of the safety impact of the various bicycle treatment types. Additionally, it is important to identify sensor types that have the potential to advance field data collection and traffic monitoring in multi-modal road environments. In this dissertation, three approaches, namely crash analysis, traffic conflict analysis, and analysis of driver speeding and glancing behavior, were implemented to investigate the safety impact of bicycle treatments at the segment- and the intersection-levels on bicycle safety. Prediction models were developed to predict bicycle-motorized vehicle crashes at road segments and signalized intersections, and traffic conflicts between straight-going bicyclists and right-turning vehicles at signalized intersections. Driver speeding and glancing behavior was analysed for the segment and the intersection levels. A mode classification framework to classify trajectories recorded using a radar-based sensor was developed to test the feasibility of using radar-based sensors in field studies. The findings of this dissertation contribute to bicycle safety research in terms of quantifying the safety impact of various bicycle treatment types and how to assess and also, by showing how to assess bicycle safety. The findings of this research have the potential to stand as a valuable tool for transportation policymakers and officials in charge of establishing safe bicycle networks

Mobility and Equity for New York's Transit-Starved Neighborhoods: The Case for Full-Featured Bus Rapid Transit

New York City's public transportation system moves millions of people every day. But an increasing number who live in outer borough neighborhoods are stuck with unreliable transit options and long travel times tracked in hours, not minutes.It does not have to be this way.Developed by the Pratt Center for Community Development and funded by the Rockefeller Foundation, this report highlights the limitations of New York City's current public transit system, the adverse effects those limitations have on our economy and quality of life, and the role Bus Rapid Transit (BRT) can play in remedying these transit inequities.BRT has transformed cities across the world from Mexico City to Barcelona to Cleveland. At a fraction of the cost to build just a mile of subway rail, BRT gives riders a reliable way to get where they need to go.BRT is effective. It is innovative. And it could be the solution for New York's transit-starved neighborhoods

Judicial Discipline and Judicial Independence

The question of judicial accountability and independence arises primarily in the context of state courts. When it comes to accountability, it is state judges who must be concerned about threates to their independence

USING THE VEHICLE ROUTING PROBLEM (VRP) TO PROVIDE LOGISTICS SOLUTIONS IN AGRICULTURE

Agricultural producers consider utilizing multiple machines to reduce field completion times for improving effective field capacity. Using a number of smaller machines rather than a single big machine also has benefits such as sustainability via less compaction risk, redundancy in the event of an equipment failure, and more flexibility in machinery management. However, machinery management is complicated due to logistics issues. In this work, the allocation and ordering of field paths among a number of available machines have been transformed into a solvable Vehicle Routing Problem (VRP). A basic heuristic algorithm (a modified form of the Clarke-Wright algorithm) and a meta-heuristic algorithm, Tabu Search, were employed to solve the VRP. The solution considered optimization of field completion time as well as improving the field efficiency. Both techniques were evaluated through computer simulations with 2, 3, 5, or 10 vehicles working simultaneously to complete the same operation. Furthermore, the parameters of the VRP were changed into a dynamic, multi-depot representation to enable the re-route of vehicles while the operation is ongoing. The results proved both the Clarke-Wright and Tabu Search algorithms always generated feasible solutions. The Tabu Search solutions outperformed the solutions provided by the Clarke-Wright algorithm. As the number of the vehicles increased, or the field shape became more complex, the Tabu Search generated better results in terms of reducing the field completion times. With 10 vehicles working together in a real-world field, the benefit provided by the Tabu Search over the Modified Clarke-Wright solution was 32% reduction in completion time. In addition, changes in the parameters of the VRP resulted in a Dynamic, Multi-Depot VRP (DMDVRP) to reset the routes allocated to each vehicle even as the operation was in progress. In all the scenarios tested, the DMDVRP was able to produce new optimized routes, but the impact of these routes varied for each scenario. The ability of this optimization procedure to reduce field work times were verified through real-world experiments using three tractors during a rotary mowing operation. The time to complete the field work was reduced by 17.3% and the total operating time for all tractors was reduced by 11.5%. The task of a single large machine was also simulated as a task for 2 or 3 smaller machines through computer simulations. Results revealed up to 11% reduction in completion time using three smaller machines. This time reduction improved the effective field capacity