# American Institute of Mathematical Sciences

October  2017, 37(10): 5191-5209. doi: 10.3934/dcds.2017225

## The Riemann Problem at a Junction for a Phase Transition Traffic Model

 Department of Mathematics and its Applications, University of Milano Bicocca, Via R. Cozzi 55, 20125 Milano, Italy

* Corresponding author: M. Garavello

Received  October 2016 Revised  May 2017 Published  June 2017

Fund Project: The authors were partially supported by the INdAM-GNAMPA 2015 project "Balance Laws in the Modeling of Physical, Biological and Industrial Processes"

We extend the Phase Transition model for traffic proposed in [8], by Colombo, Marcellini, and Rascle to the network case. More precisely, we consider the Riemann problem for such a system at a general junction with $n$ incoming and $m$ outgoing roads. We propose a Riemann solver at the junction which conserves both the number of cars and the maximal speed of each vehicle, which is a key feature of the Phase Transition model. For special junctions, we prove that the Riemann solver is well defined.

Citation: Mauro Garavello, Francesca Marcellini. The Riemann Problem at a Junction for a Phase Transition Traffic Model. Discrete & Continuous Dynamical Systems - A, 2017, 37 (10) : 5191-5209. doi: 10.3934/dcds.2017225
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##### References:
The free phase $F$ and the congested phase $C$ resulting from (1) in the coordinates, from left to right, $(\rho,\eta)$ and $(\rho, \rho v)$. In the $(\rho,\eta)$ plane, the curves $\eta= \check w \rho$, $\eta= \hat w \rho$ and the curve $\eta= \frac{V_{\max}}{\psi(\rho)}\rho$ that divides the two phases are represented. The densities $\sigma_-$ and $\sigma_+$ are given by the intersections between the previous curves. Similarly in the $(\rho, \rho v)$ plane, the curves $\rho v= \check w \psi(\rho)\rho$, $\rho v= \hat w \psi(\rho)\rho$ and the densities $\sigma_-$ and $\sigma_+$ are represented
The case $(\bar \rho,\bar \eta)\in C$. The set $\mathcal T_{inc}\left(\bar \rho, \bar \eta\right)$ it is represented in red in the coordinates, from left to right, $(\rho,\eta)$ and $(\rho, \rho v)$. The set $\mathcal T_{inc}^f \left(\bar \rho, \bar \eta\right)$ is represented on the $\rho v$ axis in the $(\rho, \rho v)$ plane
The case $(\bar \rho,\bar \eta)\in F$. The set $\mathcal T_{inc}\left(\bar \rho, \bar \eta\right)$ it is represented in red in the coordinates, from left to right, $(\rho,\eta)$ and $(\rho, \rho v)$. The set $\mathcal T_{inc}^f \left(\bar \rho, \bar \eta\right)$ is represented on the $\rho v$ axis in the $(\rho, \rho v)$ plane
The case $(\bar \rho,\bar \eta)\in F$. The set $\mathcal T_{out}\left(w, \bar \rho, \bar \eta \right)$ it is represented in red in the coordinates, from left to right, $(\rho,\eta)$ and $(\rho, \rho v)$. The set $\mathcal T_{out}^f \left(w,\bar \rho, \bar \eta\right)$ is represented on the $\rho v$ axis in the $(\rho, \rho v)$ plane
The case $(\bar \rho,\bar \eta)\in C$. The set $\mathcal T_{out}\left(w, \bar \rho, \bar \eta \right)$ it is represented in red in the coordinates, from left to right, $(\rho,\eta)$ and $(\rho, \rho v)$. The set $\mathcal T_{out}^f \left(w,\bar \rho, \bar \eta\right)$ is represented on the $\rho v$ axis in the $(\rho, \rho v)$ plane
The case $(\bar \rho,\bar \eta)\in F$ in an outgoing road for the approach in Subsection 4.1. The set of all the possible traces it is represented in red in the coordinates, from left to right, $(\rho,\eta)$ and $(\rho, \rho v)$. The corresponding set of flows is represented on the $\rho v$ axis in the $(\rho, \rho v)$ plane
The case $(\bar \rho,\bar \eta)\in C$ in an outgoing road for the approach in Subsection 4.1. The set of all the possible traces it is represented in red in the coordinates, from left to right, $(\rho,\eta)$ and $(\rho, \rho v)$. The corresponding set of flows is represented on the $\rho v$ axis in the $(\rho, \rho v)$ plane
The situation in the outgoing road related to the approach of Subsection 4.1. Left, in the $\left(\rho, \eta\right)$-plane, the states $\left(\rho_3^\ast, \eta_3^\ast\right)$ and $\left(\bar \rho_3, \bar \eta_3\right)$, connected through the middle state $\left(\rho^m, \eta^m\right)$. Right, in the $(t,x)$-plane, the waves generated by the Riemann problem. Note that the first wave has negative speed, so that it is not contained in the feasible region of the outgoing road
The case $\gamma_{1}^{*}+\gamma_{2}^{*}=\Gamma_{3}^{w_{3}}$. At left the case $\gamma_1^* < \Gamma_1$ and $\gamma_2^* < \Gamma_2$. At right the case $\gamma_1^* = \Gamma_1$
The case $\gamma_{1}^{*}+\gamma_{2}^{*}<\Gamma_{3}^{w_{3}}$
 [1] João-Paulo Dias, Mário Figueira. On the Riemann problem for some discontinuous systems of conservation laws describing phase transitions. Communications on Pure & Applied Analysis, 2004, 3 (1) : 53-58. doi: 10.3934/cpaa.2004.3.53 [2] Constantine M. Dafermos. A variational approach to the Riemann problem for hyperbolic conservation laws. Discrete & Continuous Dynamical Systems - A, 2009, 23 (1&2) : 185-195. doi: 10.3934/dcds.2009.23.185 [3] Yanbo Hu, Wancheng Sheng. The Riemann problem of conservation laws in magnetogasdynamics. Communications on Pure & Applied Analysis, 2013, 12 (2) : 755-769. doi: 10.3934/cpaa.2013.12.755 [4] Yu Zhang, Yanyan Zhang. Riemann problems for a class of coupled hyperbolic systems of conservation laws with a source term. Communications on Pure & Applied Analysis, 2019, 18 (3) : 1523-1545. doi: 10.3934/cpaa.2019073 [5] Weishi Liu. Multiple viscous wave fan profiles for Riemann solutions of hyperbolic systems of conservation laws. Discrete & Continuous Dynamical Systems - A, 2004, 10 (4) : 871-884. doi: 10.3934/dcds.2004.10.871 [6] Zhi-Qiang Shao. Lifespan of classical discontinuous solutions to the generalized nonlinear initial-boundary Riemann problem for hyperbolic conservation laws with small BV data: shocks and contact discontinuities. Communications on Pure & Applied Analysis, 2015, 14 (3) : 759-792. doi: 10.3934/cpaa.2015.14.759 [7] Alberto Bressan, Anders Nordli. The Riemann solver for traffic flow at an intersection with buffer of vanishing size. Networks & Heterogeneous Media, 2017, 12 (2) : 173-189. doi: 10.3934/nhm.2017007 [8] Anupam Sen, T. Raja Sekhar. Structural stability of the Riemann solution for a strictly hyperbolic system of conservation laws with flux approximation. Communications on Pure & Applied Analysis, 2019, 18 (2) : 931-942. doi: 10.3934/cpaa.2019045 [9] Francesca Marcellini. Existence of solutions to a boundary value problem for a phase transition traffic model. Networks & Heterogeneous Media, 2017, 12 (2) : 259-275. doi: 10.3934/nhm.2017011 [10] Tai-Ping Liu, Shih-Hsien Yu. Hyperbolic conservation laws and dynamic systems. Discrete & Continuous Dynamical Systems - A, 2000, 6 (1) : 143-145. doi: 10.3934/dcds.2000.6.143 [11] Tatsien Li, Wancheng Sheng. The general multi-dimensional Riemann problem for hyperbolic systems with real constant coefficients. Discrete & Continuous Dynamical Systems - A, 2002, 8 (3) : 737-744. doi: 10.3934/dcds.2002.8.737 [12] Alberto Bressan, Marta Lewicka. A uniqueness condition for hyperbolic systems of conservation laws. Discrete & Continuous Dynamical Systems - A, 2000, 6 (3) : 673-682. doi: 10.3934/dcds.2000.6.673 [13] Gui-Qiang Chen, Monica Torres. On the structure of solutions of nonlinear hyperbolic systems of conservation laws. Communications on Pure & Applied Analysis, 2011, 10 (4) : 1011-1036. doi: 10.3934/cpaa.2011.10.1011 [14] Stefano Bianchini. A note on singular limits to hyperbolic systems of conservation laws. Communications on Pure & Applied Analysis, 2003, 2 (1) : 51-64. doi: 10.3934/cpaa.2003.2.51 [15] Fumioki Asakura, Andrea Corli. The path decomposition technique for systems of hyperbolic conservation laws. Discrete & Continuous Dynamical Systems - S, 2016, 9 (1) : 15-32. doi: 10.3934/dcdss.2016.9.15 [16] Wancheng Sheng, Tong Zhang. Structural stability of solutions to the Riemann problem for a scalar nonconvex CJ combustion model. Discrete & Continuous Dynamical Systems - A, 2009, 25 (2) : 651-667. doi: 10.3934/dcds.2009.25.651 [17] Peng Zhang, Tong Zhang. The Riemann problem for scalar CJ-combustion model without convexity. Discrete & Continuous Dynamical Systems - A, 1995, 1 (2) : 195-206. doi: 10.3934/dcds.1995.1.195 [18] Alberto Bressan, Fang Yu. Continuous Riemann solvers for traffic flow at a junction. Discrete & Continuous Dynamical Systems - A, 2015, 35 (9) : 4149-4171. doi: 10.3934/dcds.2015.35.4149 [19] Boris Andreianov, Mohamed Karimou Gazibo. Explicit formulation for the Dirichlet problem for parabolic-hyperbolic conservation laws. Networks & Heterogeneous Media, 2016, 11 (2) : 203-222. doi: 10.3934/nhm.2016.11.203 [20] Mapundi K. Banda, Michael Herty. Numerical discretization of stabilization problems with boundary controls for systems of hyperbolic conservation laws. Mathematical Control & Related Fields, 2013, 3 (2) : 121-142. doi: 10.3934/mcrf.2013.3.121

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