In METROPOLIS2, a road network is composed of a collection of edges and a collection of
vehicle types.
A road network is thus represented by two CSV or Parquet files:
Identifier of the edge (used in some input files and used in the output).
source
Integer
Mandatory
No negative value
Identifier of the source node of the edge.
target
Integer
Mandatory
No negative value, different from source
Identifier of the target node of the edge.
speed
Float
Mandatory
Positive number
The base speed on the edge when there is no congestion, in meters per second.
length
Float
Mandatory
Positive number
The length of the edge, from source node to target node, in meters.
lanes
Float
Optional
Positive number
The number of lanes on the edge (for this edge’s direction). The default value is 1.
speed_density.type
String
Optional
Possible values: "FreeFlow", "Bottleneck", "ThreeRegimes"
Type of speed-density function used to compute congested travel time. If null, the free-flow speed-density function is used.
speed_density.capacity
Float
Mandatory if speed_density.type is "Bottleneck", ignored otherwise
Positive number
Capacity of the road’s bottleneck when using the bottleneck speed-density function. Value is expressed in meters of vehicle headway per second.
speed_density.min_density
Float
Mandatory if speed_density.type is "ThreeRegimes", ignored othewise
Between 0.0 and 1.0
Edge density below which the speed is equal to free-flow speed.
speed_density.jam_density
Float
Mandatory if speed_density.type is "ThreeRegimes", ignored othewise
Between 0.0 and 1.0, larger than speed_density.min_density
Edge density above which the speed is equal to speed_density.jam_speed.
speed_density.jam_speed
Float
Mandatory if speed_density.type is "ThreeRegimes", ignored othewise
Positive number
Speed at which all the vehicles travel in case of traffic jam, in meters per second.
speed_density.beta
Float
Mandatory if speed_density.type is "ThreeRegimes", ignored othewise
Positive number
Parameter to compute the speed in the intermediate congested case.
bottleneck_flow
Float
Optional
Positive number
Maximum incoming and outgoing flow of vehicles at the edge’s entry and exit bottlenecks, in PCE per second. In null, the incoming and outgoing flow capacities are assumed to be infinite.
constant_travel_time
Float
Optional
Positive number
Constant travel-time penalty for each vehicle traveling through the edge, in seconds. If null, there is no travel-time penalty.
overtaking
Boolean
Optional
If true, a vehicle that is pending at the end of the edge to enter its outgoing edge is not prevending the following vehicles to access their outgoing edges. Default value is true.