Pamina

PAMINA (short for Parallel Microscopic Network Algorithm) was designed to simulate large scale road traffic networks on a microscopic scale (individual vehicles) using UNIX workstation clusters.

Components

The simulation suite consists of three major components:

• Planner: The planner replans a certain fraction of an existing route set based upon the travel time feedback provided by previous runs of the microsimulation. The input and output format is the original TRANSIMS route file format.

• Route Converter: The route converter is able to convert the TRANSIMS route file format into the PAMINA file format. At the same time it optionally “clips” the routes from the network used for re-planning to the usually smaller network used for the microsimulation.
• Microsimulator PAMINA: The microsimulator PAMINA is the core of the simulation suite. It reads the route file provided by the route converter and executes the routes contained therein on a parallel computing platform.

Features of the Microsimulator

• Execution of Route-sets: The simulation is driven by a list of route-plans called route-set. Each route-plan consists of an origin, a departure time, a list of link Ids describing the route, a destination, and a scheduled arrival time. All route-plans of a route-set are sorted by departure time. During the simulation the simulator instantiates one vehicle per route-set at the given departure time. If the location where the vehicle is to be inserted is blocked by other vehicles, the vehicle is appended to a queue for later insertion. As soon as a vehicle has been inserted it follows is route-plan through the network until it reaches its final destination where it will be removed.

• Street Segments (Links): The dynamics of motion correspond to the asymmetric two-lane cellular automaton for traffic flow developed by Nagel and Schreckenberg. For links with more than two lanes, the rule-set has been extended to prevent collisions by simultaneously changing vehicles. The speed limit can be individually set for each link. The length is given by the Euclidean distance of the two adjoining intersections or by a predefined logical length.

• Intersections: Intersections are modeled by adding a road-block to all incoming lanes. Vehicles which are in a range of v_max from the intersection are scanned and, if necessary, moved to their correct destination links. At signalized intersections, a time schedule determines which incoming links are scanned (green) and which are inactive (red).

• Online Routing: The built-in router can be used to re-route a certain fraction of vehicles identified by their plan numbers. It uses the current link velocities to compute alternative paths which are assigned to the vehicles if they meet certain quality requirements.

Documentation

The PAMINA simulation suite comes with a manual in PDF format. For a list of changes to the suite see the ChangeLog.

Supported Platforms

Prerequisites For Compiling And Running the Suite

The suite depends on a handful of libraries and tools. Most of them are available as open source packages on any unix system. These are:

• GNU g++ (3.4.4)
• GNU zip (1.3.5)
• GNU make (3.80)
• GNU m4 (1.4)
• GNU bison (1.875d)
• GNU flex (2.5.31)
• Python (2.3.4)

For generating the statistical diagrams from the simulation output one optionally needs the following tools:

• GNU awk (3.1.3)
• Gnuplot (4.0 patch level 0)

For generating GIF files of the statistical diagrams one optionally needs the following tools:

• ppmtogif (10.0)

The version numbers listed above are the ones currently used for PAMINA development. Slightly older or newer versions should work in most cases.

However, the core libraries for the parallelization may be harder to come by. This is either

• Message Passing Interface 1.0.12 (MPI) or
• Parallel Virtual Machine 3.4.4 (PVM).

The home page of PVM has been down for a while. That’s why a tar archive of version 3.4.4 has been included in the Pamina archive (see below).

Download

Scenarios

Scenarios serve as examples and test setups for PAMINA. Currently, there are two scenarios.

Links

• TRANSIMS: Traffic research project at the Los Alamos National Laboratory. Most of the data that was used for PAMINA comes from the test beds of TRANSIMS.
• NRW-FVU: Research initiative North Rhine-Westphalia Research Cooperative Traffic Simulation and Impacts on the Environment which investigates the phenomena of vehicular traffic and its impacts on the environment.
• See my dissertation.
• See my publications.