Clockwise hysteresis loops in the Macroscopic Fundamental Diagram: An effect of network instability

Purpose Road pricing is an efficient strategy for managing urban traffic to relieve congestion. The macroscopic fundamental diagram (MFD), which relates the average network density and flow, is a simple tool for assessing road pricing effects on transportation network performance. However, recent research indicates that it may have complexity (an MFD hysteresis loop), especially for city-scale networks. Although ignoring MFD hysteresis may provide inaccurate results, pricing models that consider this hysteresis are scarce. This paper aims to assess road pricing effects on network performance considering MFD hysteresis characteristics. Design/methodology/approach This paper evaluated different pricing strategies spatially and temporally and compared network performance based on MFD shape in the presence of MFD hysteresis loops. These strategies were developed on a multimodal (cars and buses) network using a multi-agent transport simulation (MATSim). Findings This study found that pricing some links for a short duration with an optimum charge calculated based on the MFD provides higher travel time savings than the previous relevant studies. Originality/value These findings may facilitate assessing road pricing effects on multimodal network performance considering MFD hysteresis.

Download Full-text

A network-wide anticipatory control of an urban network using macroscopic fundamental diagram

Transportmetrica B Transport Dynamics ◽

10.1080/21680566.2021.1878966 ◽

2021 ◽

Vol 9 (1) ◽

pp. 415-436

Author(s):

Nadia Moshahedi ◽

Lina Kattan ◽

Richard Tay

Keyword(s):

Anticipatory Control ◽

Fundamental Diagram ◽

Urban Network ◽

Macroscopic Fundamental Diagram

Download Full-text

A Modified Cellular Automaton Model for Accounting for Traffic Behaviors during Signal Change Intervals

Journal of Advanced Transportation ◽

10.1155/2018/8961454 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12

Author(s):

Chih-Cheng Hsu ◽

Yu-Chiun Chiou

Keyword(s):

Microscopic Analysis ◽

Traffic Signal ◽

Traffic Signal Control ◽

Fundamental Diagram ◽

Macroscopic Fundamental Diagram ◽

Proposed Model ◽

Signal Change ◽

Ca Model ◽

Speed Adjustment ◽

Diagram Analysis

Previous cellular automata (CA) models have been developed for simulating driver behaviors in response to traffic signal control. However, driver behaviors during traffic signal change intervals, including cross/stop decision and speed adjustment, have not yet been studied. Based on this, this paper aims to propose a change interval CA model for replicating driver’s perception and response to amber light based on stopping probability and speed adjusting functions. The proposed model has been validated by exemplified and field cases. To investigate the applicability of the proposed model, macroscopic and microscopic analyses are conducted. Although the macroscopic fundamental diagram analysis reveals only a small decrease in maximum traffic flow rates with considering driver behaviors in change intervals, in the microscopic analysis, the proposed model can present reasonable vehicular trajectories and deceleration rates during slowdown process.

Download Full-text

Synthesis and Ferroelectric Properties of Sol–Gel Derived Intergrowth-Superlattice-Structured SrBi4Ti4O15-Bi4Ti3O12 Thin Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.197-198.1781 ◽

2011 ◽

Vol 197-198 ◽

pp. 1781-1784

Author(s):

Hua Wang ◽

Jian Li ◽

Ji Wen Xu ◽

Ling Yang ◽

Shang Ju Zhou

Keyword(s):

Thin Films ◽

Remanent Polarization ◽

Annealing Temperature ◽

Ferroelectric Properties ◽

Sol Gel ◽

Hysteresis Loops ◽

Si Substrates ◽

Gel Processing ◽

Coercive Electric Field ◽

Clockwise Hysteresis

Intergrowth-superlattice-structured SrBi4Ti4O15–Bi4Ti3O12(SBT–BIT) films prepared on p-Si substrates by sol-gel processing. Synthesized SBT–BIT films exhibit good ferroelectric properties. As the annealing temperature increases from 600°C to 700°C, the remanent polarization Prof SBT–BIT films increases, while the coercive electric field Ecdecreases. SBT–BIT films annealed at 700°C have a Prvalue of 18.9µC/cm2which is higher than that of SBT (16.8µC/cm2) and BIT (14.6µC/cm2), and have the lowest Ecof 142 kV/cm which is almost the same as that of SBT and BIT. The C-V curves of Ag/SBT-BIT/p-Si heterostructures show the clockwise hysteresis loops which reveal the memory effect due to the polarization. The memory window in C-V curve of Ag/SBT-BIT/p-Si is larger than that of Ag/SBT/p-Si heterostructure or Ag/BIT/p-Si heterostructure.

Download Full-text