Combined Alternate-Direction Lane Assignment and Reservation-Based Intersection Control

2020 ◽  
Vol 21 (4) ◽  
pp. 1779-1789 ◽  
Author(s):  
Nikola Mitrovic ◽  
Igor Dakic ◽  
Aleksandar Stevanovic
Keyword(s):  
Alternate Direction ◽  
Intersection Control

Impact of Shared Lanes on Performance of the Combined Flexible Lane Assignment and Reservation-based Intersection Control

2021 ◽  
pp. 036119812110642
Author(s):  
Farzaneh Azadi ◽  
Nikola Mitrovic ◽  
Aleksandar Stevanovic
Keyword(s):  
Autonomous Vehicles ◽  
Fixed Time ◽  
Urban Environments ◽  
Entire System ◽  
Traffic Flows ◽  
Optimal Amount ◽  
Time Control ◽  
Alternate Direction ◽  
Left And Right ◽  
Intersection Control

Benefiting from opportunities offered by connected and autonomous vehicles (CAVs), a concept called Combined Alternate-Direction Lane Assignment and Reservation-based Intersection Control (CADLARIC) was proposed recently for management of directionally unrestricted traffic flows in urban environments. In CADLARIC, resolution of vehicular conflicts is distributed between links and intersections to prevent intersections from turning into traffic bottlenecks. Although CADLARIC has shown promising results, it has been observed that, once traffic volume on a certain lane reaches “physical capacity,” adding more traffic on that lane degrades performance of the entire system, as each lane is exclusively dedicated to a particular movement. To overcome this problem, Combined Flexible Lane Assignment and Reservation-based Intersection Control (CFLARIC) is proposed, which offers more flexible lane assignment possibilities. While CFLARIC allows left- and right-turning lanes to be shared with through traffic, it is unclear how much through traffic should be assigned to turning lanes. Thus, this study investigates which strategy is the most beneficial when reassigning extra through traffic to the turning lanes. This goal is divided into two objectives: 1. Identify which lanes should be shared, and 2. Find a close-to-optimal amount of through traffic that should be assigned to the identified shared lane. The proposed CFLARIC strategies are compared with Fixed-Time Control (FTC), Full Reservation-based Intersection Control (FRIC), and CADLARIC for multiple demand scenarios. The results show that the best performing CFLARIC strategies outperform FTC, FRIC, and CADLARIC for delay and number of stops, and reduce the number of conflicting situations compared with FRIC and CADLARIC.

scholarly journals The alternate direction iterative methods for generalized saddle point systems

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Shuanghua Luo ◽  
Angang Cui ◽  
Cheng-yi Zhang
Keyword(s):  
Saddle Point ◽  
Iterative Methods ◽  
Iterative Schemes ◽  
Numerical Example ◽  
Convergence Results ◽  
Alternate Direction ◽  
Saddle Point Matrix

Abstract The paper studies two splitting forms of generalized saddle point matrix to derive two alternate direction iterative schemes for generalized saddle point systems. Some convergence results are established for these two alternate direction iterative methods. Meanwhile, a numerical example is given to show that the proposed alternate direction iterative methods are much more effective and efficient than the existing one.

Evaluating Pedestrian Crash-Prone Locations to Formulate Policy Interventions for Improved Safety and Walkability at Sidewalks and Crosswalks

2021 ◽  
pp. 036119812110041
Author(s):  
Mallikarjun Patil ◽  
Bandhan Bandhu Majumdar ◽  
Prasanta K. Sahu
Keyword(s):  
Condition Index ◽  
Signal Timing ◽  
Physical Separation ◽  
Weighted Sum Method ◽  
Policy Interventions ◽  
Research Findings ◽  
Exclusive Right ◽  
Hierarchy Process ◽  
Intersection Control ◽  
Indian Cities

This study presents a methodology for evaluating a set of crash-prone sidewalk and crosswalk locations in an urban area with respect to their existing walkability condition and recommending improvement needs. Initially, a set of 15 sidewalk specific and 10 crosswalk specific attributes relevant to India were identified from the literature. Subsequently, the analytical hierarchy process was used to estimate relative weights associated with the attributes from the perspective of relevant experts. A weighted sum method was then used to formulate a Sidewalk Condition Index (SCI) and Crosswalk Condition Index (CCI) for evaluating the condition of the existing pedestrian sidewalks and crosswalk infrastructures. Ten locations across Hyderabad with the highest pedestrian fatalities during the last three calendar years were selected as study locations. The location specific SCI and CCI estimates were used to prioritize the locations with regard to their existing condition and infrastructural requirements. Results indicated that sidewalk attributes such as sidewalk lighting, cleanliness, physical separation of traffic, and traffic speed, and crosswalk attributes such as conflicts with crossing traffic, crosswalk illumination, and intersection control, influenced safety and walkability significantly. Measures such as the provision of exclusive right-of-way for pedestrians, maintaining the sidewalk quality, enforcing no jaywalking, re-design of signal timing with pedestrian phase, and provision of zebra crossings and refuge islands, would improve walkability at pedestrian crash-prone locations across Hyderabad. This proposed methodology and the research findings could act as a critical tool to improve the overall safety and walkability of sidewalks and crosswalks in Indian cities.

scholarly journals Semi-Degree Threshold for Anti-Directed Hamiltonian Cycles

10.37236/3610 ◽  
2015 ◽  
Vol 22 (4) ◽  
Author(s):  
Louis DeBiasio ◽  
Theodore Molla
Keyword(s):  
Directed Graph ◽  
Hamiltonian Cycle ◽  
Minimum Degree ◽  
Directed Graphs ◽  
Hamiltonian Cycles ◽  
Alternate Direction ◽  
Degree Conditions

In 1960 Ghouila-Houri extended Dirac's theorem to directed graphs by proving that if $D$ is a directed graph on $n$ vertices with minimum out-degree and in-degree at least $n/2$, then $D$ contains a directed Hamiltonian cycle. For directed graphs one may ask for other orientations of a Hamiltonian cycle and in 1980 Grant initiated the problem of determining minimum degree conditions for a directed graph $D$ to contain an anti-directed Hamiltonian cycle (an orientation in which consecutive edges alternate direction). We prove that for sufficiently large even $n$, if $D$ is a directed graph on $n$ vertices with minimum out-degree and in-degree at least $\frac{n}{2}+1$, then $D$ contains an anti-directed Hamiltonian cycle. In fact, we prove the stronger result that $\frac{n}{2}$ is sufficient unless $D$ is one of two counterexamples. This result is sharp.

Barrier-Free Ring Structures and Pedestrian Overlaps in Signalized Intersection Control

2012 ◽  
Vol 2311 (1) ◽  
pp. 132-141
Author(s):  
Peter G. Furth ◽  
Theo H. J. Muller ◽  
Maria Salomons ◽  
Tomas A. Bertulis ◽  
Peter J. Koonce
Keyword(s):  
Signalized Intersection ◽  
Free Ring ◽  
Ring Structures ◽  
Intersection Control ◽  
Barrier Free
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