Tram line 4 in Paris

Robustness analysis of operations with the new branch to Clichy-Montfermeil

The Aulnay-Bondy has been the first application of tram-train in France. The line, dubbed “Egg Cup Line”, opened in 1875 as a heavy rail connection between the east and west networks of Paris. The development of the tram-train concept inspired plans to reinvigorate the ligne des Coquetiers using this system that seemed ideal. It solved the problems caused by the rail crossings by transforming them into simple road junctions. It reduced disruptions in the urban landscape and expanded the use of trams in urban transportation all while greatly increasing service. This technology was finally adopted, and in 2006 the tam-train service started.


A new branch splitting at Gargan and connecting the Clichy-Montfermeil plateau is currently under construction. It will allow residents of Clichy-sous-Bois, Montfermeil, and nearby communes to reach Bondy (RER E) or Aulnay-sous-Bois (RER B) much faster than they currently do using the bus. It will also create a new way to access major employment centres such as the Roissy-Charles-de-Gaulle Airport.” Being a regular tram line operating aside existing roads, the new branch might significantly reduce service reliability on the main trunk. On the other hand compensating the risk of delays with overlong margins would greatly reduce the attractiveness of the new service. Thus designing a timetable that allows operating with the minimum running times compatible with the time losses at the intersections is key for success of the line.

trenolab, together with its partner Alius Consulting, has been asked by SNCF Mobilité to simulate operations considering the impact of road traffic. trenolab developed a set of specific functions to reproduce the drive on-sight and traffic lights in trenissimo. The study demonstrated the feasibility and robustness of the proposed plan which entered into service at the end of 2019.

Our tasks:

  • Infrastructure planning
  • Microscopic simulation model development
  • Microscopic simulation model calibration
  • Microscopic stochastic simulation
  • 2019/05 - 2019/08
  • France
  • SNCF Mobilité – Agence Tram-Train
  • Timetable Planning, Integrated Service and Infra Planning
  • TRENOplus, trenissimo