Contents

Download and parse map data

Download OpenStreetMap data

You can use the following two methods to download the OpenStreetMap data:

1. OpenStreetMapOfficial: choose Export -> OverpassAPI (otherwise the size of the bounding box size is limited).

OpenStreetMap Official

By this way, you will get the complete OSM data (xml), then you can use osm_filter.osm_way_filter() to get the layer you need.

2. Overpass API (recommended): directly use overpass API to download the layer you need. The sample query code is attached in the appendix Appendix A: Query code.

Overpass API

In this way, you will directly get the layer you need.

Parse OpenStreetMap data

The downloaded OpenStreetMap xml file can be parsed using the mtldp.mtlmap.build_network_from_xml():

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import mtldp.mtlmap as mtlmap
network = mtlmap.build_network_from_xml("*.osm")

This will return you a well-structured class mtldp.mtlmap.Network.

Appendix A: Query code

Here is an example of the query code using the OverpassAPI.

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<!--
This has been generated by the overpass-turbo wizard.
The original search was:
“highway=* and highway!=footway and highway!=pedestrian and -highway!=path”
-->
<osm-script output="xml" timeout="25"><!-- fixed by auto repair -->
    <!-- gather results -->
    <union>
        <!-- query part for: “highway=* and highway!=footway and highway!=pedestrian and "-highway"!=path” -->
        <query type="node">
            <has-kv k="highway"/>
            <has-kv k="highway" modv="not" v="footway"/>
            <has-kv k="highway" modv="not" v="pedestrian"/>
            <has-kv k="highway" modv="not" v="path"/>
            <has-kv k="highway" modv="not" v="steps"/>
            <has-kv k="highway" modv="not" v="service"/>
            <has-kv k="highway" modv="not" v="stop"/>
            <has-kv k="highway" modv="not" v="crossing"/>
            <has-kv k="highway" modv="not" v="bus_stop"/>
            <has-kv k="highway" modv="not" v="elevator"/>
            <has-kv k="highway" modv="not" v="emergency_access_point"/>
            <has-kv k="highway" modv="not" v="give_way"/>
            <has-kv k="highway" modv="not" v="mini_roundabout"/>
            <has-kv k="highway" modv="not" v="passing_place"/>
            <has-kv k="highway" modv="not" v="rest_area"/>
            <has-kv k="highway" modv="not" v="speed_camera"/>
            <has-kv k="highway" modv="not" v="street_lamp"/>
            <has-kv k="highway" modv="not" v="turning_circle"/>
            <has-kv k="highway" modv="not" v="turning_loop"/>
            <has-kv k="highway" modv="not" v="toll_gantry"/>

            <bbox-query {{bbox}}/>
        </query>
        <query type="way">
            <has-kv k="highway"/>
            <has-kv k="highway" modv="not" v="footway"/>
            <has-kv k="highway" modv="not" v="pedestrian"/>
            <has-kv k="highway" modv="not" v="path"/>
            <has-kv k="highway" modv="not" v="steps"/>
            <has-kv k="highway" modv="not" v="service"/>


            <bbox-query {{bbox}}/>
        </query>
        <query type="relation">
            <has-kv k="highway"/>
            <has-kv k="highway" modv="not" v="footway"/>
            <has-kv k="highway" modv="not" v="pedestrian"/>
            <has-kv k="highway" modv="not" v="path"/>
            <has-kv k="highway" modv="not" v="steps"/>
            <has-kv k="highway" modv="not" v="service"/>


            <bbox-query {{bbox}}/>
        </query>
    </union>
    <!-- print results -->
    <print mode="meta"/><!-- fixed by auto repair -->
    <recurse type="down"/>
    <print mode="meta" order="quadtile"/><!-- fixed by auto repair -->
</osm-script>

Appendix B: Network classes

Network

mtldp.mtlmap.Network is the highest level class that includes all different kinds of information of links, segments, lane sets, and nodes defined blow.

Network

Node

Node is parsed from the node in the OpenStreetMap data. Established based on a general mtldp.mtlmap.Node class that contains essential attributes including node id, GPS coordinates, we further divide the nodes into different categories including mtldp.mtlmap.SegmentConnectionNode, mtldp.mtlmap.SignalizedNode, mtldp.mtlmap.UnSignalizedNode, and mtldp.mtlmap.EndNode. In the figure below, the red mark denotes a signalized node.

Node

Segment

mtldp.mtlmap.Segment is used to define a road segment that has the uniform tags and parameters (speed limit, lane number and usage, etc.). Each segment is directly generated from a way from the OpenStreetMap data (we also have a class mtldp.mtlmap.OsmWay that is directly parsed from the OpenStreetMap data). In the figure below, the blue arrows denote the segments. There might be multiple segments between two nodes.

Segment

LaneSet

mtldp.mtlmap.LaneSet class denotes a set of lanes that has the same downstream direction (e.g. through, right turn, left turn). The blue arrows in the figure below denote the lane sets. For example, the blue arrows that are connected to the left intersection represent the through movement and left turn movement.

LaneSet
Tutorial Visualize the network