• Public Transport

Introduction#

Most public transport uses fixed routes (busses, trams and trains) and this page describes how to model this type of transport. For demand responsive transport that is more flexible see Taxi.

The descriptions below describe how to model busses but the same rules apply for trams, subways and trains.

Bus Stops#

It is possible to define positions of bus stops and let vehicles ("busses") stop at these positions for a pre-given time. Definitions of bus stop locations in SUMO have the following format:

<busStop id="<BUS_STOP_ID>" lane="<LANE_ID>" startPos="<STARTING_POSITION>" endPos="<ENDING_POSITION>" [lines="<LINE_ID>[ <LINE_ID>]*"]/>

That means that a bus stop is an area on a lane. The parameters have the following meanings:

Access Lanes#

Each bus or train stop may have additional child elements to model access from other parts of the network (e.g. road access to a stop on the rail network). This takes the following form:

<busStop id="myStop" lane="A_0" startPos="230" endPos="250">
   <access lane="B_0" pos="150"/>
</busStop>

Access information is added automatically for railway stops when importing public transport information from OSM.

The value doors is currently only used when exiting a train or bus. The starting position for a subsequent walk of the exiting passengers will be randomly chosen among the door positions of the train or bus. The door positions themselves cannot be defined but they are derived from the number of carriages and the number of doors per carriage of the vehicle, see carriage definition.

Letting Vehicles stop at a bus stop#

Vehicles must be informed that they must stop at a bus stop. The following example shows how this can be done (taken from <SUMO_HOME>/examples/sumo/busses):

<additional xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://sumo.dlr.de/xsd/additional_file.xsd">
    <busStop id="busstop1" lane="2/1to1/1_0" startPos="20" endPos="40" lines="100 101 102"/>
    <busStop id="busstop2" lane="1/2to0/2_0" startPos="20" endPos="40" lines="100 101"/>
    <busStop id="busstop3" lane="0/1to0/0_0" startPos="20" endPos="40" lines="100 101 102"/>
    <busStop id="busstop4" lane="1/0to2/0_0" startPos="20" endPos="40" lines="100 101"/>

    <vType id="BUS" accel="2.6" decel="4.5" sigma="0" length="12" minGap="3" maxSpeed="70" color="1,1,0" guiShape="bus"/>

    <vehicle id="0" type="BUS" depart="0" color="1,1,0">
        <route edges="2/0to2/1 2/1to1/1 1/1to1/2 1/2to0/2 0/2to0/1 0/1to0/0 0/0to1/0 1/0to2/0 2/0to2/1"/>
        <stop busStop="busstop1" duration="20"/>
        <stop busStop="busstop2" duration="20"/>
        <stop busStop="busstop3" duration="20"/>
        <stop busStop="busstop4" duration="20"/>
    </vehicle>
</additional>

What is defined here is a vehicle named "0" being a "BUS". "BUS" is a referenced vehicle type declared earlier. The vehicle has an embedded route (written by hand in this case) and a list of stop places. Each stop place is described by two attributes, "bus_stop" and "duration" where "bus_stop" is the name of the bus stop the vehicle shall halt at and "duration" is the time the vehicle shall wait at the bus stop in seconds. Please note that the order of bus stops the vehicle shall halt at must be correct.

For a complete list of attributes for the "stop"-element of a vehicle see Definition_of_Vehicles,_Vehicle_Types,_and_Routes#Stops.

Incomplete Route Definition#

It is also possible to define a bus route without defining all intermediate edges:

   <trip id="0" type="BUS" depart="0" color="1,1,0" from="2/0to2/1" to="2/0to2/1">
       <stop busStop="busstop1" duration="20"/>
       <stop busStop="busstop2" duration="20"/>
       <stop busStop="busstop3" duration="20"/>
       <stop busStop="busstop4" duration="20"/>
   </trip>

The vehicle will take the fastest path between from-edge and to-edge that visits all stops in their correct order.

Even the trip attributes 'from' and 'to' can be omitted to let the bus start at the first stop and end at the last. Using departPos="stop", the vehicle will be inserted directly at the first stop in its route:

   <trip id="0" type="BUS" depart="0" color="1,1,0" departPos="stop">
       <stop busStop="busstop1" duration="20"/>
       <stop busStop="busstop2" duration="20"/>
       <stop busStop="busstop3" duration="20"/>
       <stop busStop="busstop4" duration="20"/>
   </trip>

Public Transport Schedules#

In most cases, public transport runs according to a fixed schedule. Such a schedule must be defined using the until attribute in the stops. Vehicles in the simulation will adhere to the schedule as they cannot leave a stop before the until-time is reached but they may still be delayed due to traffic. When until and duration are used, duration defines the minimum stopping time which can also cause delayed departures when already arriving late at a stop.

Single vehicles and trips#

When defining until values for a vehicle and trip, the values denote absolute simulation times. Note, that seconds or human-readable times may be used.

<trip="bus" from="beg" to="end" line="bus" depart="6:0:0">
     <stop busStop="busStopA" until="6:30:00"/>
     <stop busStop="busStopB" until="6:32:30"/>
     <stop busStop="busStopC" until="23700"/>
</trip>

Flows#

When defining a vehicle flow the until times are absolute times for the first vehicle in the flow. For all later vehicles, the times will be shifted according to later departure times (period * vehicleIndex).

The example below defines a flow that inserts two vehicles. The first vehicle will stop until 10,110,210 and the second vehicle will stop until 310,410,510:

<flow id="bus" from = "beg" to ="end" line="bus" begin="0" end="301" period="300">
    <stop busStop="busStopA" until="10"/>
    <stop busStop="busStopB" until="110"/>
    <stop busStop="busStopC" until="210"/>
</flow>

Stops in a stand-alone route#

Stops may also be part of a route that is defined by itself (with an id) and referenced by vehicles or flows. In that case the until times will be interpreted as 'times after vehicle departure'.

The example below defines a flow that inserts two vehicles. The first vehicle will depart at 500 and stop until 510,610,710. The second vehicle will depart at 800 and stop until 810,910,1010:

<route id="busRoute" edges="A B C D E">
    <stop busStop="busStopA" until="10"/>
    <stop busStop="busStopB" until="110"/>
    <stop busStop="busStopC" until="210"/>
</route>

<flow id="bus" route="busRoute" line="bus" begin="500" end="801" period="300"/>

Looped routes#

Looped routes can be defined by repeating edges and stops in the above definitions. To shorten the input description, a route may also be defined with the attributes repeat and cycleTime:

<route id="busRoute" edges="A B C D E" repeat="3" cycleTime="300">
    <stop busStop="busStopA" until="10"/>
    <stop busStop="busStopB" until="110"/>
    <stop busStop="busStopC" until="210"/>
</route>

This repeats the route edges and the stops three times. The until times of the stops are shifted by 300s in each cycle and thus the simulation expands this to the following schedule:

<route id="busRoute" edges="A B C D E A B C D E A B C D E" repeat="3" cycleTime="300">
    <stop busStop="busStopA" until="10"/>
    <stop busStop="busStopB" until="110"/>
    <stop busStop="busStopC" until="210"/>
    <stop busStop="busStopA" until="310"/>
    <stop busStop="busStopB" until="410"/>
    <stop busStop="busStopC" until="510"/>
    <stop busStop="busStopA" until="610"/>
    <stop busStop="busStopB" until="710"/>
    <stop busStop="busStopC" until="810"/>
</route>

In contrast to a period flow (which also repeats a given stop sequence), this simulation keeps a single vehicle in the loop. This allows for delays from one loop to be carried over into the next iteration. Flow definitions can make use of repeating routes in order to have multiple vehicles serving the repeating loop at the same time.

Further Schedule Attributes#

The following stop attributes are relevant for public transport schedules:

• arrival: Defines expected arrival at the public transport stop. When set this causes arrivalDelay to be computed and written in stop-output. It also enables results for the function traci.vehicle.getStopArrivalDelay.
• extension: The maximum time by which a public transport stop may be extended due to boarding passengers
• line: A new line attribute to be set on the vehicle when reaching the stop. This is currently ignored by the intermodal router!
• tripId: Updates the tripId parameter of the vehicle when reaching the stop. This parameter has no impact on simulation behavior but may be useful to reflect real-world bookkeeping on the vehicle status over the course of an operating day
• started: Defines actual arrival time at the stop (i.e. from a real world data source or a prior simulation run)
• ended: Defines actual time at which the stop ended (i.e. from a real world data source or a prior simulation run). Can be used to override the 'until' attribute by setting sumo option --use-stop-ended.

The attributes started and ended are used to account for real-life modifications to a railway schedule (train order changes), when generating railSignalConstraints for schedule-based railway simulation.

Visualization Example#

Generated by plotXMLAttributes.py.

Stopping without defining a bus stop#

You may also let a vehicle stop at another position than a bus stop. The short definition of a vehicle's stop is:

<stop bus_stop="<BUS_STOP_ID>" | ( lane="<LANE_ID>" endPos="<POSITION_AT_LANE>" ) duration="<HALTING_DURATION>"/>

This means you can either use a bus stop or a lane position to define where a vehicle has to stop. For a complete list of attributes for the stop element of a vehicle see Definition_of_Vehicles,_Vehicle_Types,_and_Routes#Stops.

Passengers#

Additional definitions are necessary if the persons using the public transport lines shall be modeled as well.

To make use of intermodal routing, additional constrains on public transport definition must be met.

Importing Public Transport#

OSM#

The osmWebWizard tool can be used to import public transport data from OpenStreetMap for a selected area.

This import uses an intermediate data format (ptlines-file) to describe public transport lines. The usage of this line data is explained at Tutorials/PT_from_OpenStreetMap.

GTFS#

The tool gtfs2pt.py can be used to import public transport data for a geo-referenced network.

Automatic Schedule Generation#

The tool ptlines2flows.py can be used to generated a public transport schedule with 'until' and 'duration' values for a given sequence of stops. The schedule times are derived by running a simulation in the background.