Contents

Network classes

Network class

Static network class

class mtldp.mtlmap.Network

Class for the general network

Main Attributes
Classes for the roads
Classes for the nodes
Others

  • .bounds the bounding box of the network, mtldp.utils.BoundingBox

  • .networkx_graph networkx graph

__init__()

Initialize self. See help(type(self)) for accurate signature.

build_networkx_graph(graph_mode=<GraphMode.SEGMENT: 1>, networkx_type=0)

Build the self to a NetworkX graph object

See reference for networkx: https://networkx.org/, this package will allow you to apply different types of algorithms based on network including shortest path, etc.

Parameters
shortest_path_between_nodes(source_node, end_node, weight_attrib='length')

Calculate the shortest path between unordinary nodes (the source node and end node should not be an ordinary node). This implementation is based on NetworkX.

Attention

Please pay attention to the NetworkX graph mode, there are different modes for building the networkX graph and the shortest path function also differs under different mode. See mtldp.mtlmap.GraphMode for more information.

Parameters

  • source_node (str) – source node id

  • end_node (str) – end node id

  • weight_attrib (str) – the chosen weight to calculate the shortest path

Returns

{"nodes": [str], "weight": float, "edges": [str]}, "weight" is None if no connected path.

Network of certain TOD (with data)

Mode selection

class mtldp.mtlmap.GraphMode(value)

Mode selection for generating the NetworkX graph object class:mtldp.mtlmap.Network.build_networkx_graph.

Mode

Method

.LINK

Convert each intersection to a node while convert each link to an edge

.SEGMENT

Convert non-ordinary node (intersection, segment connection) to a node and each segment to an edge

.LANESET

Convert each laneset to a node and the edge inherit the properties of the downstream laneset
class mtldp.mtlmap.MapMode(value)

Mode selection for parsing the OpenStreetMap data mtldp.mtlmap.build_network_from_xml().

See map parsing flowchart for more information.

The mode in the lower row (more accurate mode) generate more layers than that of upper row, which means that it will also generate the layers that can be generated by the mode in the upper row.

Mode

Output layers

Applications

.MAP_MATCHING

Segment, Node, OsmWay

Trajectory data map matching

.ACCURATE

Link, Segment

Split trajectory into movements

.ROUGH

LaneSet, ConflictPoint

Build CTM model, etc.

Roads classes

OsmWay

class mtldp.mtlmap.OsmWay(way_id=None, node_list=None, osm_attrib=None, osm_tags=None)

OsmWay corresponds to the “way” in the original osm data

Main attributes

  • .osm_tags a dictionary contains all the tags in the original osm data.

  • .osm_attrib a dictionary contains all the attributes in the original osm data.

  • .way_id a integer for OSM way ID

  • .node_list a list of nodes on the way

  • .length length of the way in meters

  • .geometry the GPS coordinates along the way

  • .forward_heading the heading angle at the start of the way (range: (-180,180]))

  • .backward_heading the heading angle at the end of the way (range: (-180,180]))

  • .lane_number number of lanes

  • .forward_lanes number of lanes from the start of the way to the end of the way

  • .backward_lanes number of lanes from the end of the way to the start of the way

  • .name name of the way

  • .speed_limit speed limit of the way in m/s

generate_basic_info()

extract useful information from the osm attrib and tags

current extracted information includes:

  • lane information (# and assignment)

  • speed limit (25mph if null)

  • name

Returns

update_way_geometry()

Update the geometric information of a link

Returns

None

Movement

class mtldp.mtlmap.Movement

A movement reflects the user perspective and is defined by the user type and the action that is taken (e.g. through, right turn, left turn)

Main Attributes

-index: -movement_id: -upstream_link: -downstream_link: -signal_status: -node: -direction: -upstream_length: -protected: -geometry: -trajectory_collection:

Segment

class mtldp.mtlmap.Segment

A segment is a proportion of a link that share share the same number of lanes.

Main attributes

  • .segment_id a integer for segment ID. 0 or 1 (denotes the direction ) is added at the end of the .osm_way as the .segment_id

  • .osm_way a integer for the original OSM way ID

  • .osm_tags a dictionary contains all the tags in the original osm data.

  • .osm_attrib a dictionary contains all the attributes in the original osm data.

  • .belonged_link the link ID that the segment belongs to

  • .laneset_list the list of lane sets that belong to the segment

  • .laneset_num the number of lane sets that belong to the segment

  • .speed_limit speed limit of the segment in m/s

  • .length length of the segment in meters

  • .geometry the GPS coordinates along the segment

  • .lane_number number of lanes of the segment

  • .lane_assignment the assignment of the lanes of the segment. For example, “all_through” means all lanes on the segment are through movements. “left|through;right” means the segments include both left turn movement through (right turn) movement. If unavailable, this value is null.

  • .heading the heading angle of the segment (range: (-180,180]))

  • .from_direction the direction from which the segment originates. For example, if the segment originates from south, this value is “S”.

  • .node_list a list of nodes on the segment

  • .upstream_node the upstream node of the segment

  • .downstream_node the downstream node of the segment

  • .upstream_segment a list of the upstream segment ID of this segment

  • .downstream_segment a list of the downstream segment ID of this segment

  • .downstream_direction_info a dictionary that represents the direction of the downstream segments. For example, {'l': '4116329441', 'r': '4126838890', 's': '87279680'} means left turn downstream segment is 4116329441. Through movement downstream segment is 87279680, and right turn downstream segment is 4126838890

add_downstream_segment(seg_id)

Add an downstream segment if not exists

Parameters

seg_id – str

Returns

None

add_upstream_segment(seg_id)

Add an upstream segment if not exists

Parameters

seg_id – str

Returns

None

generate_lanesets(assignments=None)

Initiate the lane sets of the segment

Returns

list of :class:mtldp.mtlmap.laneset

get_distance_to_intersections()

Get the distance to the upstream and downstream intersection (start of the segment)

Returns

float, float

classmethod init_from_way(osmway, direction)

Initiate a segment using the osm way

Parameters

  • osmway – mtldp.mtlmap.Osmway

  • direction – “backward” or “forward”

Returns

None

LaneSet

class mtldp.mtlmap.LaneSet
LaneSet is a set of lanes that has the same downstream direction (e.g. through movement, left turn, right turn).

It can be used to build CTM or LTM model.

Main attributes

  • .laneset_id a integer for laneset ID. The lane set index within the segment is added to the segment ID. For example, if the segment ID is 1768090910, and the laneset index is 0, this value should be “1768090910_0”

  • .type type of the road. Could be “internal”, “source”, or “destination”

  • .belonged_segment the segment ID that this lane set belongs to

  • .belonged_link the link ID that this lane set belongs to

  • .turning_direction the movement of this lane set. For example, ‘s’ means through movement (straight). ‘r’ means right turn movement, and ‘l’ means left turn movement. The value can also be the combination of ‘s’, ‘r’ and ‘l’

  • .length length of the lane set in meters

  • .speed_limit speed limit of the lane set in m/s

  • .lane_number number of lanes of the lane sets

  • .heading the heading angle of the lane sets (range: (-180,180]))

  • .from_direction the direction from which the lane set originates. For example, if the lane set originates from south, this value is “S”.

  • .geometry the GPS coordinates along the lane set

  • .downstream_lanesets the downstream lane sets that it connects to

  • .turning_ratio_list the list of turning ratio information. The value is None if unavailable

  • .upstream_node the upstream node of the lane set

  • .downstream_node the downstream node of the lane set

  • .phase_id the ID of the phase associated with the lane set

compute_cumulative_travel_time(alpha)

Objective function of the BPR link performance function

Parameters

alpha – float

Returns

float

compute_travel_time()

Compute the travel time according to the link performance function

Returns

None

classmethod init_from_segment(segment, direction, lane_number, insegment_offset)

Initialize laneset from the input segment

Parameters

  • segment – mtldp.mtlmap.Segment

  • direction – str

  • lane_number – int

  • insegment_offset – int

Returns

mtldp.mtlmap.Laneset

Nodes classes

General Node class

class mtldp.mtlmap.Node(node_id=None, osm_attrib=None, osm_tags=None)

Node corresponds to the node in osm (xml) data,

Node is also the father class for the following classes:

  • MTTTrajectoryData.mimap.SignalizedNode

  • MTTTrajectoryData.mimap.SignalizedNode

  • MTTTrajectoryData.mimap.UnSignalizedNode

  • MTTTrajectoryData.mimap.EndNode

Main attributes

  • .node_id unique id of the node.

  • .osm_attrib attributes of the node in the original osm data (dict)

  • .osm_tags tags of the node in the original osm data (dict)

  • .type type of the node (“ordinary”, “connector”, “signalized”, “unsignalized”, “end”)

  • .latitude and .longitude node GPS coordinate

  • .upstream_segments upstream segments of this node (list of str)

  • .downstream_segments downstream segments of this node (list of str)

add_connector(connector)

Add connector to the node

Parameters

connector – mtldp.mtlmap.Connector

Returns

None

add_movement(movement)

Add a movement to the node

Parameters

movement – mtldp.mtlmap.Movement

Returns

generate_basic_info()

Add latitude and longitude attributes

Returns

None

classmethod init_from_node(node)

Initialize a node from the input node

Parameters

node – mtldp.mtlmap.Node

Returns

mtldp.mtlmap.Node

is_intersection()

Check if a node is an intersection

Returns

True if this node is an intersection

Return type

bool

is_ordinary_node()

Check if a node is an ordinary node

Returns

True if this node is an ordinary node

Return type

bool

Segment connector

class mtldp.mtlmap.SegmentConnectionNode

The node that connects the segments (all through, no left/right turn)

Signalized node

class mtldp.mtlmap.SignalizedNode

Class for signalized intersection

Inherit from MTTTrajectoryData.mimap.Node

Additional Attributes

  • .timing_plan the signal controller of this node, mimap.SignalTimingPlan.

Unsignalized node

class mtldp.mtlmap.UnSignalizedNode

Class for unsignalized node

Inherit from MTTTrajectoryData.mimap.Node

Additional Attributes

End node

class mtldp.mtlmap.EndNode

Signal Classes

Signal Timing Plan

Map data and network Network cores