Minimizing the Average Delay at Intersections via Presignals and Speed Control

© 2018 Mina Ghanbarikarekani et al. Urban intersections have been well recognized as bottlenecks of urban transport systems. It is thus important to propose and implement strategies for increasing the efficiency of public and private transportation systems as a whole. In order to achieve this goal, an additional signal could be set up near the intersection to give priority to buses through stopping vehicles in advance of the main intersection as a presignal. It has been increasingly popular in urban cities. While presignals indeed reduce the average delay per traveler, they cause extra stops of private vehicles, which might compromise the overall efficiency, safety, and sustainability. This paper aims to propose a model to improve presignals by reducing the vehicles' number of stops behind the presignals. By applying the method, vehicles would be able to adjust their speed based on traffic conditions as well as buses' speed and approach. Numerical analyses have been conducted to determine the conditions required for implementing this method

Minimizing the stop time of private vehicles at intersections with LRT signal priority systems

© 2020 The Authors. Published by Elsevier B.V. There are some strategies suggested to improve the performance of intersections and increase the demand for public vehicles by prioritizing them. To this end, several methods have been used such as Transit Signal Priority (TSP) system for Light Rail transit (LRT). LRT signal priority is a timing strategy that gives priority to LRTs at signalized intersections through changing the sequence of phases, extending green time and reducing red time at LRT's phase. In this paper, we propose a model to improve LRT signal priority systems. The developed model minimizes the green extension and red reduction of LRT's phase by estimating an optimal speed for LRTs reaching the stop line. Consequently, the priority of LRTs would be maintained while the performance of private vehicles would be improved by decreasing their stop time

An Algorithm for Reducing Vehicles’ Stop Behind the Bus Pre-signals

© 2019, Springer Nature Singapore Pte Ltd. One of the current controversial issues is mitigating traffic congestion in big cities. Public vehicles play a vital role in solving this matter, so it has been taken into consideration to improve not only the public transit’s infrastructure but also its functionality. More specifically, it is aimed to encourage travellers to use public vehicles. In order to serve this purpose, public transit systems’ delay needs to be decreased by prioritising them. Nowadays, pre-signal, as a modern strategy for prioritising buses, has been proposed. Pre-signal is an additional signal that is applied near the intersection to give buses priority through stopping vehicles in advance of the main intersection, and it reduces the average delay per traveller. However, it has to be mentioned that pre-signals penalise private vehicles by extra stops. This paper aims to propose a model to improve the pre-signal strategy by reducing the vehicles’ number of stops behind the pre-signals. This model would cause vehicles to be able to adjust their speed based on traffic conditions and traffic signal as well as buses’ speed and approach

Optimization of Signalized Intersections Equipped with LRV Signal Priority Systems by Minimizing Cars’ Stop Time *

There are some strategies suggested to improve the performance of intersections and increase the demand for public vehicles by providing them priority. In order to achieve this goal, several policies have been used such as Transit Signal Priority (TSP) system for Light Rail Vehicle (LRV). LRV signal priority is a timing strategy that gives priority to LRVs at signalized intersections. More specifically, this strategy is based on changing the sequence of phases, extending green time and reducing red time of LRV's phase. Although this method has considerable benefits for LRVs, it penalizes private vehicles by increasing their delay and stop time at intersections. This paper aims to propose a model to improve LRV signal priority systems. The modifying model for LRV signal priority systems minimizes the green extension and red reduction of LRV's phase by using linear programming (LP) method to calculate an optimal speed for LRVs reaching the stop line. Consequently, LRVs are prioritized while the performance of private vehicles would be improved