Citation

Paipuri M, Leclercq L. Transp. Res. B Methodol. 2020; 133: 257-290.

Copyright

(Copyright © 2020, Elsevier Publishing)

DOI

10.1016/j.trb.2020.01.007

PMID

unavailable

Abstract

Bi-modal or 3D-MFD relates the accumulation of cars, buses to total production at the network level. The current work provides a detailed discussion of extended MFD-based models namely, accumulation-based and trip-based models that accounts for bi-modal flows through 3D-MFD. In addition, delay accumulation-based models, also known as exit-flow models in classical traffic flow theory, are revisited. Fundamental modeling differences between different MFD-based models are illustrated using a benchmark test case. A new FIFO-based entry flow function is also proposed in order to address the inconsistencies of the conventional entry flow function in the context of the 3D-MFD case. A novel weak internal FIFO discipline is proposed to circumnavigate the violation of internal FIFO order during network unloading in the delay accumulation-based model. MFD-based models are verified using the solutions of micro-simulations performed on an idealized grid network. The importance of separating the 3D-MFD into partial car and bus 3D-MFDs is highlighted. Moreover, it is also shown that partial bus 3D-MFD should be further split when dedicated bus lanes are present in the network to account for unequal mean speeds between different bus lanes.

Language: en

Keywords

3D Macroscopic fundamental diagram; Bi-modal; Delay accumulation-based model; FIFO; MFD-based modeling; Micro-simulation