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Transportation Networks 2

A fork of Transportation Networks with better TNTP format:

  • Easier to parse
  • Numbering of nodes start with 0 (and not 1)
  • Removed redundant zeros from some OD tables

Format

There are four types of TNTP files in this repo:

  • Network file (.net.tntp)
  • Origin-destination matrix/table file (.odm.tntp)
  • Edge flow file (.flow.tntp)
  • Node file (.node.tntp)

<Text> in angle brackets in format snippets denotes some value that is explained below the snippet.

Network file

Describes structure of the oriented graph representing transportation network.

NODES:<nodes>
ZONES:<zones>
EDGES:<edges>
END
<start> <end> <capacity> <freeFlow> <length> <speed> <toll> <b> <power> <type>
<start> <end> <capacity> <freeFlow> <length> <speed> <toll> <b> <power> <type>
<start> <end> <capacity> <freeFlow> <length> <speed> <toll> <b> <power> <type>
...

The file starts with header:

  • <nodes> - Number of nodes in network. The set of nodes is then represented by the numbers 0..(nodes-1).
  • <zones> - Number of zones in network. Zones are special nodes, they are the sources and sinks of traffic flow in the network (see OD matrix). The set of zones is a subset of set of nodes and is represented by number 0..(zones-1).
  • <edges> - Number of edges in network. Also the number of lines after header.

The header ends with END line, after which start lines describing each edge:

  • <start> - Node from which this edge originates.
  • <end> - Node to which this edge points.
  • <capacity> - Practical capacity of traffic link represented by this edge.
  • <freeFlow> - Free flow time of traffic link represented by this edge. The time one car would take to cross this link if the link would be otherwise empty.
  • <length> - Irrelevant for STA algorithms.
  • <speed> - Irrelevant for STA algorithms.
  • <toll> - Irrelevant for STA algorithms.
  • <b> - Parameter of BPR function. Might aswell be always 0.15.
  • <power> - Parameter of BPR function. Might aswell be always 4.
  • <type> - Irrelevant for STA algorithms.

OD matrix file

Describes the origin-destination matrix/table in form of a sparse matrix. In this matrix, the element in position (i, j) represents traffic flow originating in zone i going to zone j. The matrix is thus a square matrix of rank equal to number of zones.

ZONES:<zones>
FLOW:<flow>
END
<i> <j>:<flow> <j>:<flow> <j>:<flow> ...
<i> <j>:<flow> <j>:<flow> <j>:<flow> ...
<i> <j>:<flow> <j>:<flow> <j>:<flow> ...
...

The file starts with header:

  • <zones> - Rank of the matrix.
  • <flow> - Total flow in the OD matrix. Sum of all its elements.

The header ends with END line, after which start the sparse matrix. Each line start with matrix row number <i> followed by pairs of column numbers <j> and according flows <flow>. Pairs where flow is zero are not present.

Known issues

  • Munich network is a mess, not yet converted
  • Barcelona seems to have messed up capacities (always 1) and edge-dependent BPR function coefficients
  • missing mirror edges in some networks (mirror edges are required by B algorithm)