IntermodalRouting

Basic Concepts#

Every person may have multiple modes of transport to chose from. Currently those are walking (which is assumed to be always possible), riding by public transport and going by car. Intermodal routing uses person trips to define a trip of a person including mode changes.

Defining intermodal demand#

To define intermodal demand use the <personTrip>-element:

<routes>
  <person id="p0" depart="0">
    <personTrip from="beg" to="end"/>
  </person>
</routes>

The tool randomTrips.py may be used with the option --persontrips to generate random intermodal demand.

Defining available cars#

To allow usage of a car, either the attribute modes="car" or the vType of the available car must be specified for the personTrip:

<routes>
  <vType id="typ0" vClass="passenger"/>
  <person id="p0" depart="0">
      <personTrip from="beg" to="end" vTypes="typ0"/>
  </person>
</routes>

Defining public transport#

In order to be included by in the public transport routing, flows (also vehicles or trips) must be defined with a public transport schedule.

An example for a bus line and a person that may uses this line are given below:

<routes xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="http://sumo.dlr.de/xsd/routes_file.xsd">
    <flow id="bus" from = "beg" to ="end" line="bus" begin="0" end="1000" period="300">
                <stop busStop="busStopA" until="10"/>
                <stop busStop="busStopB" until="110"/>
                <stop busStop="busStopC" until="210"/>
    </flow>
    <person id="p0" depart="0">
        <personTrip from="beg" to="end" modes="public"/>
    </person>
</routes>

Note

A vehicle/flow/trip must define the line attribute to be considered as public transport. Every vehicle with a line attribute is considered public transport and may be used for routing regardless of its capacity.

Switching between modes#

Not all places in a traffic network are suitable for transfering between walking and riding modes (i.e. parking facilities may be needed to switch from a private car to walking or public transport). The following options are provided for this purpose:

  • --persontrip.transfer.car-walk: set a list of any of the following values: parkingAreas, ptStops, allJunctions (default parkingAreas)
  • --persontrip.transfer.taxi-walk: set a list of any of the following values: ptStops, allJunctions (default allJunctions)
  • --persontrip.transfer.walk-taxi: set a list of any of the following values: ptStops, allJunctions (default allJunctions)

The meaning of the argument values is as follows:

  • parkingAreas: transfer only at edges with a <parkingArea> element
  • ptStops: transfer only at public transport stops (i.e. <busStop>)
  • allJunctions: transfer on any edge that allows the vehicle as well as pedestrians, also transfer at any junction if it connects an edge that allows the vehicle with another edge that allows pedestrians.

Intermodal Cost Function#

Generally, intermodal routing may consider multiple criteria such as travel time, costs, reliability and convenience. Currently, duarouter only takes the following travel time into account:

  • Individual vehicle transport uses the standard vehicle routing costs. This can be influenced by loading custom weights via option --weight-files
  • Walking uses the maximum walking speed of the person and multiplies this with a factor, configurable via option --persontrip.walkfactor <FLOAT> (default 0.9). The factor is used to account for delays due to intersections and pedestrian interactions
  • Walking against the direction of traffic may be discouraged on edges that are shared with vehicles. This can be configured with option --persontrip.walk-opposite-factor (default 1.0).
  • Public transport uses the time to the next train departure (waiting time) and the difference of the until-times between successive stops
  • Accessing a stop from another part of the network takes time in direct proportion to the straight-line distance with a configurable factor (netconvert option --railway.access-factor <FLOAT>). The distance can be customized in the access definition.
  • The time (expected) time penalty when calling a taxi is set by option --persontrip.taxi.waiting-time