Definition of Vehicles, Vehicle Types, and Routes

---

Filename extension	.rou.xml
Type of content	Vehicles, Vehicle Types, and Routes
Open format?	Yes
SUMO specific?	Yes
XML Schema	routes_file.xsd

There are various applications that can be used to define vehicular demand for SUMO. Of course it is also possible to define the demand file manually or to edit generated files with a text editor. Before starting, it is important to know that a vehicle in SUMO consists of three parts:

• a vehicle type which describes the vehicle's physical properties,
• a route the vehicle shall take,
• and the vehicle itself.

Both routes and vehicle types can be shared by several vehicles. It is not mandatory to define a vehicle type. If not given, a default type is used. The driver of a vehicle does not have to be modelled explicitly. For the simulation of persons which walk around or ride in vehicles, additional definitions are necessary.

Vehicles and Routes#

Initially, we will define a vehicle with a route owned by him only:

<routes>
    <vType id="type1" accel="0.8" decel="4.5" sigma="0.5" length="5" maxSpeed="70"/>

    <vehicle id="0" type="type1" depart="0" color="1,0,0">
      <route edges="beg middle end rend"/>
    </vehicle>

</routes>

By giving such a route definition to SUMO (or SUMO-GUI), SUMO will build a red (color=1,0,0) vehicle of type "type1" named "0" which starts at time 0. The vehicle will drive along the streets "beg", "middle", "end", and as soon as it has approached the edge "rend" it will be removed from the simulation.

This vehicle has its own internal route which is not shared with other vehicles. It is also possible to define two vehicles using the same route. In this case the route must be "externalized" - defined before being referenced by the vehicles. Also, the route must be named by giving it an id. The vehicles using the route refer it using the "route"-attribute. The complete change looks like this:

<routes>
    <vType id="type1" accel="0.8" decel="4.5" sigma="0.5" length="5" maxSpeed="70"/>

    <route id="route0" color="1,1,0" edges="beg middle end rend"/>

    <vehicle id="0" type="type1" route="route0" depart="0" color="1,0,0"/>
    <vehicle id="1" type="type1" route="route0" depart="0" color="0,1,0"/>

</routes>

A vehicle may be defined using the following attributes:

Attribute Name	Value Type	Description
id	id (string)	The name of the vehicle
type	id	The id of the vehicle type to use for this vehicle.
route	id	The id of the route the vehicle shall drive along
color	color	This vehicle's color
depart	float (s) or one of triggered, containerTriggered	The time step at which the vehicle shall enter the network; see #depart. Alternatively the vehicle departs once a person enters or a container is loaded
departLane	int/string (≥0, "random", "free", "allowed", "best", "first")	The lane on which the vehicle shall be inserted; see #departLane. default: "first"
departPos	float(m)/string ("random", "free", "random_free", "base", "last")	The position at which the vehicle shall enter the net; see #departPos. default: "base"
departSpeed	float(m/s)/string (≥0, "random", "max", "desired", "speedLimit")	The speed with which the vehicle shall enter the network; see #departSpeed. default: 0
arrivalLane	int/string (≥0,"current")	The lane at which the vehicle shall leave the network; see #arrivalLane. default: "current"
arrivalPos	float(m)/string (≥0(1), "random", "max")	The position at which the vehicle shall leave the network; see #arrivalPos. default: "max"
arrivalSpeed	float(m/s)/string (≥0,"current")	The speed with which the vehicle shall leave the network; see #arrivalSpeed. default: "current"
line	string	A string specifying the id of a public transport line which can be used when specifying person rides
personNumber	int (in [0,personCapacity])	The number of occupied seats when the vehicle is inserted. default: 0
containerNumber	int (in [0,containerCapacity])	The number of occupied container places when the vehicle is inserted. default: 0
reroute	bool	Whether the vehicle should be equipped with a rerouting device (setting this to false does not take precedence over other assignment options)
via	id list	List of intermediate edges that shall be passed on rerouting Note: when via is not set, any <stop>-elements that belong to this route will automatically be used as intermediate edges. Otherwise via takes precedence.
departPosLat	float(m)/string ("random", "free", "random_free", "left", "right", "center")	The lateral position on the departure lane at which the vehicle shall enter the net; see Simulation/SublaneModel. default: "center"
arrivalPosLat	float(m)/string ("left", "right", "center")	The lateral position on the arrival lane at which the vehicle shall arrive; see Simulation/SublaneModel. by default the vehicle does not care about lateral arrival position

Repeated vehicles (Flows)#

It is possible to define repeated vehicle emissions ("flow"s), which have the same parameters as the vehicle except for the departure time. The id of the created vehicles is "flowId.runningNumber" and they are distributed either equally or randomly in the given interval. The following additional parameters are known:

Attribute Name	Value Type	Description
begin	float(s)	first vehicle departure time
end	float(s)	end of departure interval (if undefined, defaults to 24 hours)
vehsPerHour	float(#/h)	number of vehicles per hour, equally spaced (not together with period or probability)
period	float(s)	insert equally spaced vehicles at that period (not together with vehsPerHour or probability)
probability	float([0,1])	probability for emitting a vehicle each second (not together with vehsPerHour or period), see also Simulation/Randomness
number	int(#)	total number of vehicles, equally spaced

<flow id="type1" color="1,1,0"  begin="0" end= "7200" period="900" type="BUS">
    <route edges="beg middle end rend"/>
    <stop busStop="station1" duration="30"/>
</flow>

Routes#

One may notice, that the route itself also got a color definition, so the attributes of a route are:

Attribute Name	Value Type	Description
id	id (string)	The name of the route
edges	id list	The edges the vehicle shall drive along, given as their ids, separated using spaces
color	color	This route's color

There are a few important things to consider when building your own routes:

• Routes have to be connected. At the moment the simulation raises an error if the next edge of the current route is not a successor of the current edge or if the vehicle is not allowed to drive on any of the lanes. If you want the old behavior where a vehicle simply stopped at the end of the current edge and was possibly "teleported" to the next edge after a waiting time, use the Option --ignore-route-errors.
• Routes have to contain at least one edge.
• The route file has to be sorted by starting times. In fact this is only relevant, when you define a lot of routes or have large gaps between departure times. The simulation parameter --route-steps, which defaults to 200, defines the size of the time interval with which the simulation loads its routes. That means by default at startup, only routes with departure times <200 are loaded, if all the vehicles have departed, the routes up to departure time 400 are loaded etc. pp. This works only if the route file is sorted. This behavior may be disabled by specifying --route-steps 0. It is possible to load unsorted route files as an additional file which will load the whole file at once.

The first two conditions can be checked using <SUMO_HOME>/tools/route/routecheck.py, the third can be "fixed" using <SUMO_HOME>/tools/route/sort_routes.py.

Incomplete Routes (trips and flows)#

Demand information for the simulation may also take the form of origin and destination edges instead of a complete list of edges. In this case the simulation performs fastest-path routing based on the traffic conditions found in the network at the time of departure/flow begin. Optionally, a list of intermediate edges can be specified with the via attribute. The input format is exactly the same as that for the DUAROUTER application and can be found here.

<routes>
  <trip id="t" depart="0" from="beg" to="end"/>
  <flow id="f" begin="0" end="100" number="23" from="beg" to="end"/>
  <flow id="f2" begin="0" end="100" number="23" from="beg" to="end" via="e1 e23 e7"/>
</routes>

For more details on how to handle routing errors and influence the routing in this case see Demand/Automatic_Routing.

For supported attributes for flows and trips see here.

Traffic assignement zones (TAZ)#

It is also possible to let vehicles depart and arrive at traffic assignment zones (TAZ). This allows the departure and arrival edges to be selected from a predefined list of edges. Those edges are used which minimize the travel time from origin TAZ to destination TAZ. When loading trips into DUAROUTER the loaded travel times are used (with empty-network travel times as default). When loading trips into SUMO, the current travel times in the network are used as determined by the rerouting device.

<routes>
  <trip id="t" depart="0" fromTaz="taz1" toTaz="taz2"/>
</routes>

<additional>
  <taz id="<TAZ_ID>" edges="<EDGE_ID> <EDGE_ID> ..."/>
  ...
</additional>

When loading <taz> in SUMO-GUI the optional attribute shape can be used to draw an arbitrary polygon border for visualizing the traffic assignment zone.

Routing between Junctions#

Trips and flows may use the attributes fromJunction, toJunction, and viaJunctions to describe origin, destination and intermediate locations. This is a special form of TAZ-routing and it must be enabled by either setting the SUMO option --junction-taz or by loading TAZ-definitions that use the respective junction IDs. When using option --junction-taz, all edges outgoing from a junction may be used at the origin and all edges incoming to a junction may be used to reach the intermediate and final junctions.

A Vehicle's depart and arrival parameter#

Using the depart... and arrival...-attributes, it is possible to control how a vehicle is inserted into the network and how it leaves it.

depart#

Determines the time at which the vehicle enters the network (for <flow> the value of begin is used instead). If there is not enough space in the network, the actual depart time may be later.

• When using option --max-depart-delay <TIME> the vehicle is discarded if unable to depart after the given delay
• A random offset to the specified depart time is added for each vehicle when using option --random-depart-offset <TIME>
• When using the special value triggered, the vehicle will depart as soon as a person enters it.

departLane#

Determines on which lane the vehicle is tried to be inserted;

• ≥0: the index of the lane, starting with rightmost=0
• "random": a random lane is chosen; please note that a vehicle insertion is not retried if it could not be inserted
• "free": the most free (least occupied) lane is chosen
• "allowed": the "free" lane (see above) of those lane of the depart edge which allow vehicles of the class the vehicle belongs to
• "best": the "free" lane of those who allow the vehicle the longest ride without the need to lane change
• "first": the rightmost lane the vehicle may use

BTW, I like "best" at most - dkrajzew

departPos#

Determines the position on the chosen departure lane at which the vehicle is tried to be inserted;

• ≥0: the position on the lane, starting at the lane's begin; must be smaller than the starting lane's length
• "random": a random position is chosen; it is not retried to insert the vehicle if the first try fails
• "free": a free position (if existing) is used
• "random_free": at first, ten random positions are tried, if all fail, "free" is applied
• "base": the vehicle is tried to be inserted at the position which lets its back be at the beginning of the lane (vehicle's front position=vehicle length)
• "last": the vehicle is inserted with the given speed as close as possible behind the last vehicle on the lane. If the lane is empty it is inserted at the end of the lane instead. When departSpeed="max" is set, vehicle speed will not be adapted.

departSpeed#

Determines the speed of the vehicle at insertion, where maxSpeed = MIN(speedLimit * speedFactor, vTypeMaxSpeed);

• ≥0: The vehicle is tried to be inserted using the given speed. If that speed is unsafe, departure is delayed.
• "random": A random speed between 0 and maxSpeed is used, the speed may be adapted to ensure a safe distance to the leader vehicle.
• "max": The maxSpeed is used, the speed may be adapted to ensure a safe distance to the leader vehicle.
• "desired": The maxSpeed is used. If that speed is unsafe, departure is delayed.
• "speedLimit": The speed limit of the lane is used. If that speed is unsafe, departure is delayed.

arrivalLane#

Determines the speed at which the vehicle should end its route;

• "current": the vehicle will not change it's lane when nearing arrival. It will use whatever lane is more convenient to reach its arrival position. (default behavior)
• ≥0: the vehicle changes lanes to end it's route on the specified lane

arrivalPos#

Determines the position along the destination edge where the vehicle is conisdered to have arrived;

• "max": the vehicle will drive up to the end of its final lane. (default behavior)
• <FLOAT>: the position on the lane, starting at the lane's begin; Negative values count from the end of the lane
• "random": a random position is chosen at departure; If vehicle is rerouted a new random position is selected.

arrivalSpeed#

Determines the speed at which the vehicle should end its route;

• "current": the vehicle will not modify it's speed when nearing arrival. It will drive as fast as (safely) possible. (default behavior)
• ≥0: the vehicle approaches it's arrival position to end with the specified speed

Vehicle Types#

A vehicle is defined using the vType-element as shown below:

<routes>
    <vType id="type1" accel="2.6" decel="4.5" sigma="0.5" length="5" maxSpeed="70"/>
</routes>

Having defined this, one can build vehicles of type "type1". The values used above are the ones most of the examples use. They resemble a standard vehicle as used within the Stefan Krauß' thesis.

<routes>
    <vType id="type1" accel="2.6" decel="4.5" sigma="0.5" length="5" maxSpeed="70"/>
    <vehicle id="veh1" type="type1" depart="0">
        <route edges="edge1 edge2 edge3"/>
    </vehicle>
</routes>

This definition is the initial one which includes both, the definition of the vehicle's "purely physical" parameters, such as its length, its color, or its maximum velocity, and also the used car-following model's parameters. Please note that even though the car-following parameters are describing values such as max. acceleration, or max. deceleration, they mostly do not correspond to what one would assume. The maximum acceleration for example is not the car's maximum acceleration possibility but rather the maximum acceleration a driver choses - even if you have a Jaguar, you probably are not trying to go to 100km/h in 5s when driving through a city.

The default car following model is based on the work of Krauß but other models can be selected as well. Model selection and parameterization is done by setting further vType-attribures as shown below. The models and their parameters are described in the following.

<routes>
    <vType id="type1" length="5" maxSpeed="70" carFollowModel="Krauss" accel="2.6" decel="4.5" sigma="0.5"/>
</routes>

Available vType Attributes#

These values have the following meanings:

Attribute Name	Value Type	Default	Description
id	id (string)	-	The name of the vehicle type
accel	float	2.6	The acceleration ability of vehicles of this type (in m/s^2)
decel	float	4.5	The deceleration ability of vehicles of this type (in m/s^2)
apparentDecel	float	==decel	The apparent deceleration of the vehicle as used by the standard model (in m/s^2). The follower uses this value as expected maximal deceleration of the leader.
emergencyDecel	float	==decel	The maximal physically possible deceleration for the vehicle (in m/s^2).
sigma	float	0.5	Car-following model parameter, see below
tau	float	1.0	Car-following model parameter, see below
length	float	5.0	The vehicle's netto-length (length) (in m)
minGap	float	2.5	Empty space after leader [m]
maxSpeed	float	55.55 (200 km/h) for vehicles, 1.39 (5 km/h) for pedestrians	The vehicle's maximum velocity (in m/s)
speedFactor	float	1.0	The vehicles expected multiplicator for lane speed limits
speedDev	float	0.1	The deviation of the speedFactor; see below for details (some vClasses use a different default)
color	RGB-color	"1,1,0" (yellow)	This vehicle type's color
vClass	class (enum)	"passenger"	An abstract vehicle class (see below). By default vehicles represent regular passenger cars.
emissionClass	emission class (enum)	"PC_G_EU4"	An emission class (see below). By default a gasoline passenger car conforming to emission standard EURO 4 is used.
guiShape	shape (enum)	"unknown"	a vehicle shape for drawing. By default a standard passenger car body is drawn.
width	float	1.8	The vehicle's width [m] (used only for visualization with the default model, affects sublane model)
height	float	1.5	The vehicle's height [m]
collisionMinGapFactor	float	depends on carFollowModel (1.0 for most models)	The minimum fraction of minGap that must be maintained to the leader vehicle to avoid a collision event
imgFile	filename (string)	""	Image file for rendering vehicles of this type (should be grayscale to allow functional coloring)
osgFile	filename (string)	""	Object file for rendering with OpenSceneGraph (any of the file types supported by the available OSG-plugins)
laneChangeModel	lane changing model name (string)	'LC2013'	The model used for changing lanes
carFollowModel	car following model name (string)	'Krauss'	The model used for car following
personCapacity	int	4	The number of persons (excluding an autonomous driver) the vehicle can transport.
containerCapacity	int	0	The number of containers the vehicle can transport.
boardingDuration	float	0.5	The time required by a person to board the vehicle.
loadingDuration	float	90.0	The time required to load a container onto the vehicle.
latAlignment	string	center	The preferred lateral alignment when using the sublane-model. One of (left, right, center, compact, nice, arbitrary).
minGapLat	float	0.6	The desired minimum lateral gap when using the sublane-model
maxSpeedLat	float	1.0	The maximum lateral speed when using the sublane-model
actionStepLength	float	global default (defaults to the simulation step, configurable via --default.action-step-length)	The interval length for which vehicle performs its decision logic (acceleration and lane-changing). The given value is processed to the closest (if possible smaller) positive multiple of the simulation step length.

Besides values which describe the vehicle's car-following properties, one can find definitions of the assigned vehicles' shapes, emissions, and assignment to abstract vehicle classes. These concepts will be described in the following. Also, you may find further descriptions of implemented car-following models in the subsection #Car-Following Models.

Speed Distributions#

The desired driving speed usually varies among the vehicle of a fleet. In SUMO this is modeled by a speed distribution using the attributes speedFactor or speedDev. as explained below.

Vehicle class specific defaults#

When defining a vehicle type with a vClass, the following default speed-deviation will be used.

• passenger (default vClass): 0.1
• pedestrian: 0.1
• bicycle: 0.1
• truck, trailer, coach, delivery, taxi: 0.05
• tram, rail_urban, rail, rail_electric, rail_fast: 0
• emergency: 0
• everything else: 0.1

Global Configuration#

Instead of configuring speed distributions in a <vType> definition (as explained below), the SUMO-option --default.speeddev <FLOAT> can be used to set a global default. Seeting this value to 0 restores pre-1.0.0 behavior.

Defining speed limit violations explicitly#

Each vehicle has an individual speed factor which is multiplied with the speed limit (edge speed) to determine the desired driving speed (default 1.0). A vehicle with speed factor 1.2 drives up to 20% above the speed limit whereas a vehicle with speed factor 0.8 would always stay below the speed limit by 20%. By setting attributes speedFactor and speedDev as show below this individual speed factor for all vehicles of a type can be set to a fixed value.

<vType id="example" speedFactor="1.2" speedDev="0"

Defining a normal distribution for vehicle speeds#

The desired driving speed usually varies among the vehicle of a fleet. While this could be modeled by defining a new type for each vehicle and assigning a distinct speed factor for each type (as above) this would be quite cumbersome. Instead the attribute speedFactor can also be used to sample a vehicle specific speed factor from a normal distribution. The parameter can be given as "norm(mean, dev)" or "normc(mean, dev, min, max)". Using speedFactor="normc(1,0.1,0.2,2)" will result in a speed distribution where 95% of the vehicles drive between 80% and 120% of the legal speed limit. For flows, every inserted vehicle will draw an individual chosen speed multiplier as well. The resulting values in this example are capped at 20% of speedFactor at the low end to prevent extreme dawdling and at twice the recommended speed. A vehicle keeps its chosen speed multiplier for the whole simulation and multiplies it with edge speeds to compute the actual speed for driving on this edge. Thus vehicles can exceed edge speeds. However, vehicle speeds are still capped at the vehicle type's maxSpeed.

Defining a normal distribution (old style)#

An alternative way to specify speed distributions is to use numerical values for speedFactor and speedDev. In this case speedFactor defines the expected value and speedDev defines the deviation. When using this style, capping cannot be controlled and will always default to 20% and 200%. Thus the above example can also be defined as speedFactor="1" speedDev="0.1".

Additional remarks on speed distributions#

Vehicle Length#

Due to the work on car following models, we decided to use two values for vehicle length. The length-attribute describes the length of the vehicle itself. Additionally, the minGap-attribute describes the offset to the leading vehicle when standing in a jam.

This is illustrated in the following image:

Within the simulation, each vehicle needs - when ignoring the safe gap - length+minGap. But only length of the road should be marked as being occupied.

Abstract Vehicle Class#

A SUMO vehicle may be assigned to an "abstract vehicle class", defined by using the attribute vClass. These classes are used in lane definitions and allow/disallow the usage of lanes for certain vehicle types. One may think of having a road with three lanes, where the rightmost may only be used by "taxis" or "buses". The default vehicle class is passenger (denoting normal passenger cars).

The following vehicle classes exist:

vClass	bitmask bit	comment
ignoring	- (all bits set to 0)	may drive on all lanes regardless of set permissions.
private	0
emergency	1
authority	2
army	3
vip	4
pedestrian	5	lanes which only allow this class are considered to be 'sidewalks' in NETCONVERT
passenger	6	This is the default vehicle class and denotes regular passenger traffic
hov	7	High-occupancy vehicle
taxi	8
bus	9	urban line traffic
coach	10	overland transport
delivery	11	Allowed on service roads that are not meant for public traffic
truck	12
trailer	13	truck with trailer
motorcycle	14
moped	15	motorized 2-wheeler which may not drive on motorways
bicycle	16
evehicle	17	future mobility concepts such as electric vehicles which may get special access rights
tram	18
rail_urban	19	heavier than 'tram' but distinct from 'rail'. Encompasses Light Rail and S-Bahn
rail	20	heavy rail
rail_electric	21	heavy rail vehicle that may only drive on electrified tracks
rail_fast	22	High-speed-rail
ship	23	basic class for navigating waterways
custom1	24	reserved for user-defined semantics
custom2	25	reserved for user-defined semantics

These values are a "best guess" of somehow meaningful values, surely worth to be discussed. Though, in parts, they represent classes found in imported formats. They are "abstract" in the means that they are just names only, one could build a .5m long bus.

The following vehicle deprecated classes exist for maintaining backward compatibility:

deprecated vClass	replacement
public_emergency	deprecated. use 'emergency'
public_authority	deprecated, use 'authority'
public_army	deprecated, use 'army'
public_transport	deprecated, use 'bus'
transport	deprecated, use 'truck'
lightrail	deprecated, use 'tram'
cityrail	deprecated, use 'rail_urban'
rail_slow	deprecated, use 'rail'

Vehicle Emission Classes#

The emission class represents a certain emission class. It is defined using the emissionClass attribute. Possible values are given in Models/Emissions and its subsections.

Visualization#

For a nicer visualization of the traffic, the appearance of a vehicle type's vehicles may be changed by assigning them a certain shape using the guiShape attribute. These shapes are used when setting the drawing mode for vehicles to simple shapes. The following shapes are known:

• "pedestrian"
• "bicycle"
• "motorcycle"
• "passenger"
• "passenger/sedan"
• "passenger/hatchback"
• "passenger/wagon"
• "passenger/van"
• "delivery"
• "truck"
• "truck/semitrailer"
• "truck/trailer"
• "bus"
• "bus/city"
• "bus/flexible" (8.25)
• "bus/overland" (8.25)
• "rail" (24.5)
• "rail/light" (16.85)
• "rail/city" (5.71)
• "rail/slow" (9.44)
• "rail/fast" (24.775)
• "rail/cargo" (13.86)
• "evehicle"
• "ship"

Some of these classes are drawn as a sequence of carriages. The length of a single carriage is indicated in parentheses after the type. For these types, the length of the vehicleType is used as the overall length of the train (all carriages combined). For example, a vehicle with shape rail/cargo and length 70m will have 5 carriages. The number of carriages will always be a whole number and no carriage will be shorter than the length given in brackets but may be longer to meet the length requirements of the whole vehicle. When drawing vehicles with raster images, the image will be repeated for each carriage.

In addition, one can determine the width of the vehicle using the attribute width. When using shapes, one should consider that different vehicle classes (passenger vehicles or buses) have different lengths. Passenger vehicles with more than 10m length look quite odd, buses with 2m length, too.

Further parameters can be used to achieve visualization of individual rail carriages

<vType id="rail">
    <param key="carriageLength" value="20"/>
    <param key="carriageGap" value="1"/>
    <param key="locomotiveLength" value="25"/>   
</vType>

Car-Following Models#

The car-following models currently implemented in SUMO are given in the following table.

Element Name (deprecated)	Attribute Value (when declaring as attribute)	Description
carFollowing-Krauss	Krauss	The Krauß-model with some modifications which is the default model used in SUMO
carFollowing-KraussOrig1	KraussOrig1	The original Krauß-model
carFollowing-PWagner2009	PWagner2009	A model by Peter Wagner, using Todosiev's action points
carFollowing-BKerner	BKerner	A model by Boris Kerner Caution: currently under work
carFollowing-IDM	IDM	The Intelligent Driver Model by Martin Treiber Caution: Default parameters result in very conservative lane changing gap acceptance
carFollowing-IDMM	IDMM	Variant of IDMM Caution: lacking documentation
carFollowing-KraussPS	KraussPS	the default Krauss model with consideration of road slope
carFollowing-KraussAB	KraussAB	the default Krauss model with bounded acceleration (only relevant when using PHEM classes)
carFollowing-SmartSK	SmartSK	Variant of the default Krauss model Caution: lacking documentation
carFollowing-Wiedemann	Wiedemann	Car following model by Wiedemann (2-Parameters)
carFollowing-W99	W99	Car following model by Wiedemann, 10-Parameter version
carFollowing-Daniel1	Daniel1	Car following model by Daniel Krajzewicz Caution: lacking documentation
carFollowing-ACC	ACC	Car following model by Milanés V. and Shladover S.E.
carFollowing-CACC	CACC	Car following model by Milanés V. and Shladover S.E.
carFollowing-Rail	Rail	Model for various train types

Car-Following Model Parameters#

Mostly, each model uses its own set of parameters. The following table lists which parameter are used by which model(s). Details on car-following models and their parameters can be found here.

Attribute	Default	Range	Description	Models
minGap	vClass-specific	>= 0	Minimum Gap when standing (m)	all models
accel	vClass-specific	>= 0	The acceleration ability of vehicles of this type (in m/s^2)	Krauss, SKOrig, PW2009, Kerner, IDM, ACC, CACC
decel	vClass-specific	>= 0	The deceleration ability of vehicles of this type (in m/s^2)	Krauss, SKOrig, PW2009, Kerner, IDM, ACC, CACC
emergencyDecel	vClass-specific	>= decel	The maximum deceleration ability of vehicles of this type in case of emergency (in m/s^2)	Krauss, SKOrig, PW2009, Kerner, IDM, ACC, CACC
sigma	0.5	[0,1]	The driver imperfection (0 denotes perfect driving	Krauss, SKOrig, PW2009, Kerner, IDM, ACC, CACC
tau	1	>= 0	The driver's desired (minimum) time headway. Exact interpretation varies by model. For the default model Krauss this is based on the net space between leader back and follower front). For limitations, see Car-Following-Models#tau).	all Models
k				Kerner
phi				Kerner
delta	4		acceleration exponent	IDM
stepping	0.25	>= 0	the internal step length (in s) when computing follow speed	IDM
adaptFactor	1.8	>= 0	the factor for taking into account past level of service	IDMM
adaptTime	600	>= 0	the time interval (in s) for relaxing past level of service	IDMM
security			desire for security	Wiedemann
estimation			accuracy of situation estimation	Wiedemann
speedControlGain			The control gain determining the rate of speed deviation (Speed control mode)	ACC
gapClosingControlGainSpeed			The control gain determining the rate of speed deviation (Gap closing control mode)	ACC
gapClosingControlGainSpace			The control gain determining the rate of positioning deviation (Gap closing control mode)	ACC
gapControlGainSpeed			The control gain determining the rate of speed deviation (Gap control mode)	ACC
gapControlGainSpace			The control gain determining the rate of positioning deviation (Gap control mode)	ACC
collisionAvoidanceGainSpeed			The control gain determining the rate of speed deviation (Collision avoidance mode)	ACC
collisionAvoidanceGainSpace			The control gain determining the rate of positioning deviation (Collision avoidance mode)	ACC
speedControlGainCACC			The control gain determining the rate of speed deviation (Speed control mode)	CACC
gapClosingControlGainGap			The control gain determining the rate of positioning deviation (Gap closing control mode)	CACC
gapClosingControlGainGapDot			The control gain determining the rate of the positioning deviation derivative (Gap closing control mode)	CACC
gapControlGainGap			The control gain determining the rate of positioning deviation (Gap control mode)	CACC
gapControlGainGapDot			The control gain determining the rate of the positioning deviation derivative (Gap control mode)	CACC
collisionAvoidanceGainGap			The control gain determining the rate of positioning deviation (Collision avoidance mode)	CACC
collisionAvoidanceGainGapDot			The control gain determining the rate of the positioning deviation derivative (Collision avoidance mode)	CACC
CC1			Spacing Time - s	W99
CC2			Following Variation - m	W99
CC3			Threshold for Entering "Following" - s	W99
CC4			Negative "Following" Threshold - m/s	W99
CC5			Positive "Following" Threshold - m/s	W99
CC6			Speed Dependency of Oscillation - 10^-4 rad/s	W99
CC7			Oscillation Acceleration - m/s^2	W99
CC8			Standstill Acceleration - m/s^2	W99
CC9			Acceleration at 80km/h - m/s^2	W99
trainType			string id for pre-defined train type	Rail

To select a car following model the following syntax should be used:

<vType id="idmAlternative" length="5" minGap="2" carFollowModel="IDM" tau="1.0" .../>

Default Krauss Model Description#

The default model is a modification of the model defined by Stefan Krauß in Microscopic Modeling of Traffic Flow: Investigation of Collision Free Vehicle Dynamics. The implemented model follows the same idea as that of Krauß, namely: Let vehicles drive as fast as possibly while maintaining perfect safety (always being able to avoid a collision if the leader starts braking within leader and follower maximum acceleration bounds). The implemented model as in <SUMO_HOME>/src/microsim/cfmodels/MSCFModel_Krauss.cpp has the following differences:

• Different deceleration capabilities among the vehicles are handled without violating safety (the original model allowed for collisions in this case)
• The formula for safe velocity was adapted to maintain safety when using the Euler-position update rule. This was done by discretizing some of the continuous terms. The original model was defined for the Ballistic-position updated rule and would produce collisions when using Euler. See also Simulation/Basic_Definition#Defining_the_Integration_Method.

Lane-Changing Models#

The lane-changing models currently implemented in SUMO are given in the following table.

Attribute Value	Description
LC2013	The default car following model, developed by Jakob Erdmann based on DK2008 (see SUMO’s Lane-Changing Model). This is the default model.
SL2015	Lane-changing model for sublane-simulation (used by default when setting option --lateral-resolution <FLOAT>). This model can only be used with the sublane-extension. Caution: This model may technically be used without activating sublane-simulation but this usage has not been fully tested and may not work as expected.
DK2008	The original lane-changing model of sumo until version 0.18.0, developed by Daniel Krajzewicz (see Traffic Simulation with SUMO – Simulation of Urban Mobility).

Mostly, each model uses its own set of parameters. The following table lists which parameter are used by which model(s).

Attribute	Description	Models
lcStrategic	The eagerness for performing strategic lane changing. Higher values result in earlier lane-changing. default: 1.0, range [0-inf[	LC2013, SL2015
lcCooperative	The willingness for performing cooperative lane changing. Lower values result in reduced cooperation. default: 1.0, range [0-1]	LC2013, SL2015
lcSpeedGain	The eagerness for performing lane changing to gain speed. Higher values result in more lane-changing. default: 1.0, range [0-inf[	LC2013, SL2015
lcKeepRight	The eagerness for following the obligation to keep right. Higher values result in earlier lane-changing. default: 1.0, range [0-inf[	LC2013, SL2015
lcOvertakeRight	The probability for violating rules gainst overtaking on the right default: 0, range [0-1[	LC2013
lcOpposite	The eagerness for overtaking through the opposite-direction lane. Higher values result in more lane-changing. default: 1.0, range [0-inf[	LC2013
lcLookaheadLeft	Factor for configuring the strategic lookahead distance when a change to the left is necessary (relative to right lookahead). default: 2.0, range ]0-inf[	LC2013, SL2015
lcSpeedGainRight	Factor for configuring the treshold asymmetry when changing to the left or to the right for speed gain. By default the decision for changing to the right takes more deliberation. Symmetry is achieved when set to 1.0. default: 0.1, range ]0-inf[	LC2013, SL2015
lcSublane	The eagerness for using the configured lateral alignment within the lane. Higher values result in increased willingness to sacrifice speed for alignment. default: 1.0, range [0-inf]	SL2015
lcPushy	Willingness to encroach laterally on other drivers. ''default: 0, range 0 to 1	SL2015
lcPushyGap	Minimum lateral gap when encroaching laterally on other drives (alternative way to define lcPushy). ''default: minGapLat, range 0 to minGapLat	SL2015
lcAssertive	Willingness to accept lower front and rear gaps on the target lane. The required gap is divided by this value. ''default: 1, range: positive reals	LC2013,SL2015
lcImpatience	dynamic factor for modifying lcAssertive and lcPushy. default: 0 (no effect) range -1 to 1. Impatience acts as a multiplier. At -1 the multiplier is 0.5 and at 1 the multiplier is 1.5.	SL2015
lcTimeToImpatience	Time to reach maximum impatience (of 1). Impatience grows whenever a lane-change manoeuvre is blocked.. default: infinity (disables impatience growth)	SL2015
lcAccelLat	maximum lateral acceleration per second. default: 1.0	SL2015
lcTurnAlignmentDistance	Distance to an upcoming turn on the vehicles route, below which the alignment should be dynamically adapted to match the turn direction. default: 0.0 (i.e., disabled)	SL2015
lcMaxSpeedLatStanding	Upper bound on lateral speed when standing. default: maxSpeedLat (i.e., disabled)	LC2013, SL2015
lcMaxSpeedLatFactor	Upper bound on lateral speed while moving computed as lcMaxSpeedLatStanding + lcMaxSpeedLatFactor * getSpeed(). default: 1.0	LC2013, SL2015
lcLaneDiscipline	Reluctance to perform speedGain-changes that would place the vehicle across a lane boundary. default: 0.0	SL2015
lcSigma	Lateral positioning-imperfection. default: 0.0	LC2013, SL2015

The parameters are set within the <vType>:

<vType id="myType" lcStrategic="0.5" lcCooperative="0.0"/>

Junction Model Parameters#

The behavior at intersections may be configured with the parameters listed below.

Attribute	Value Type	Default	Description
jmCrossingGap	float >= 0 (m)	10	Minimum distance to pedestrians that are walking towards the conflict point with the ego vehicle. If the pedestrians are further away the vehicle may drive across the pedestrian crossing.
jmIgnoreKeepClearTime	float (s)	-1	The accumulated waiting time (see Option --waiting-time-memory) after which a vehicle will drive onto an intersection even though this might cause jamming. For negative values, the vehicle will always try to keep the junction clear.
jmDriveAfterRedTime	float (s)	-1	This value causes vehicles to violate a red light if the duration of the red phase is lower than the given threshold. When set to 0, vehicles will always drive at yellow but will try to brake at red. If this behavior causes a vehicle to drive so fast that stopping is not possible any more it will not attempt to stop. This value also applies to the default pedestrian model.
jmDriveAfterYellowTime	float (s)	-1	This value causes vehicles to violate a yellow light if the duration of the yellow phase is lower than the given threshold. Vehicles that are too fast to brake always drive at yellow..
jmDriveRedSpeed	float (m/s)	maxSpeed	This value causes vehicles affected by jmDriveAfterRedTime to slow down when violating a red light. The given speed will not be exceeded when entering the intersection.
jmIgnoreFoeProb	float	0	This value causes vehicles to ignore foe vehicles that have right-of-way with the given probability. The check is performed anew every simulation step. (range [0,1]).
jmIgnoreFoeSpeed	float (m/s)	0	This value is used in conjunction with jmIgnoreFoeProb. Only vehicles with a speed below or equal to the given value may be ignored.
jmSigmaMinor	float, scaling factor (like sigma)	sigma	This value configures driving imperfection (dawdling) while passing a minor link (ahead of the intersection after having comitted to drive and while still on the intersection).
jmTimegapMinor	float s	1	This value defines the minimum time gap when passing ahead of a prioritized vehicle.
impatience	float or 'off'	0.0	Willingess of drivers to impede vehicles with higher priority. See below for semantics.

The parameters are set within the <vType>:

<vType id="ambulance" jmDriveAfterRedTime="300" jmDriveAfterRedSpeed="5.56"/>

Impatience#

The impatience of a driver is value between 0 and 1 that grows whenever the driver has to stop unintentionally (i.e. due to a jam or waiting at an intersection). The impatience value is computed as

MAX(0, MIN(1.0, baseImpatience + waitingTime / timeToMaxImpatience))

Where baseImpatience is configured by setting the vType-attribute impatience and timeToMaxImpatience is set using the option --time-to-impatience (default 300s). Setting this option to 0 disables impatience growth. The value of baseImpatience may be negative to slow the growth of the dynamically computed impatience. It may also be defined with the value off to prevent drivers from becoming impatient.

The impatience value is used to represent a drivers willingness to impede vehicles with higher priority. At a value of 1 or above, the driver will use any gap that is safe in the sense of collision-avoidance even if it means that another vehicle has to brake as hard as it can. At a value of 0, the driver will only perform maneuvers that do not force other vehicles to slow down. Intermediate values interpolate smoothly between these extremes.

Default Vehicle Type#

If the type attribute of a vehicle is not defined it defaults to "DEFAULT_VEHTYPE". By defining a vehicle type with this id (<vType id="DEFAULT_VEHTYPE" ..../>) the default parameters for vehicles without an explicititly defined type can be changed. The change of the default vehicle type needs to occur before any reference to the type was made, so basically before any vehicle or vehicle type was defined. So it should always be at the top of the very first route file.

Route and vehicle type distributions#

Instead of defining routes and vTypes explicitly for a vehicle SUMO can choose them at runtime from a given distribution. In order to use this feature just define distributions as following:

Vehicle Type Distributions#

<routes>
    <vTypeDistribution id="typedist1">
        <vType id="type1" accel="0.8" length="5" maxSpeed="70" probability="0.9"/>
        <vType id="type2" accel="1.8" length="15" maxSpeed="50" probability="0.1"/>
    </vTypeDistribution>
</routes>

Using existing types#

<routes>
    <vType id="type1" accel="0.8" length="5" maxSpeed="70" probability="0.9"/>
    <vType id="type2" accel="1.8" length="15" maxSpeed="50" probability="0.1"/>
    <vTypeDistribution id="typedist1" vTypes="type1 type2"/>
</routes>

Route Distributions#

<routes>
    <routeDistribution id="routedist1">
        <route id="route0" color="1,1,0" edges="beg middle end rend" probability="0.9"/>
        <route id="route1" color="1,2,0" edges="beg middle end" probability="0.1"/>
    </routeDistribution>
</routes>

A distribution has only an id as (mandatory) attribute and needs a probability attribute for each of its child elements. The sum of the probability values needs not to be 1, they are scaled accordingly. Note, that probability defaults to 1.00 when not specified. At the moment the id for the children is mandatory, this is likely to change in future versions.

A distribution can be used just as using individual types and routes:

<routes>
    <vehicle id="0" type="typedist1" route="routedist1" depart="0" color="1,0,0"/>
</routes>

Stops#

Vehicles may be forced to stop for a defined time span or wait for persons by using the stop element either as part of a route or a vehicle definition as following:

<routes>
    <route id="route0" edges="beg middle end rend">
        <stop lane="middle_0" endPos="50" duration="20"/>
    </route>
    <vehicle id="v0" route="route0" depart="0">
        <stop lane="end_0" endPos="10" until="50"/>
    </vehicle>
</routes>

The resulting vehicle will stop twice, once at lane middle_0 because of the stop defined in its route and the second time because of the stop defined in the vehicle itself. The first stop will last 20 seconds the second one until simulation second 50. For a detailed list of attributes to stops see below. For a description on how to use them to simulate public transport see Simulation/Public Transport.

Stops can be childs of vehicles, routes, persons or containers.

Attribute	Type	Range	Default	Remark
busStop	string	valid busStop ids	-	if given, containerStop, chargingStation, edge, lane, startPos and endPos are not allowed
containerStop	string	valid containerStop ids	-	if given, busStop, chargingStation, edge, lane, startPos and endPos are not allowed
chargingStation	string	valid chargingStation ids	-	if given, busStop, containerStop, edge, lane, startPos and endPos are not allowed
lane	string	lane id	-	the lane id takes the form <edge_id>_<lane_index>. the edge has to be part of the corresponding route
endPos	float(m)	-lane.length < x < lane.length (negative values count backwards from the end of the lane)	lane.length
startPos	float(m)	-lane.length < x < lane.length (negative values count backwards from the end of the lane)	endPos-0.2m	there must be a difference of more than 0.1m between startPos and endPos
friendlyPos	bool	true,false	false	whether invalid stop positions should be corrected automatically
duration	float(s)	≥0	-	minimum duration for stopping
until	float(s)	≥0	-	the time step at which the route continues
extension	float(s)	≥0	-	the maximum time by which to extend the stop duration due to boarding persons and when waiting for expected persons / triggered stopping
index	int, "end", "fit"	0≤index≤number of stops in the route	"end"	where to insert the stop in the vehicle's list of stops
triggered	bool	true,false	false	whether a person may end the stop
expected	string	list of person IDs		list of persons that must board the vehicle before it may continue (only takes effect for triggered stops)
expectedContainers	string	list of container IDs		list of containers that must be loaded onto the vehicle before it may continue (only takes effect for triggered stops)
parking	bool	true,false	value of triggered	whether the vehicle stops on the road or beside
actType	string	arbitrary	'waiting'	activity displayed for stopped person in GUI and output files (only applies to person simulation)
tripId	string	arbitrary		parameter to be applied to the vehicle to track the trip id within a cyclical public transport route
line	string	arbitrary		new line attribute to be set on the vehicle when reaching this stop (for cyclical public transport route)
speed	float	positive	-	speed to be kept while driving between startPos and endPos

• If "duration" and "until" are given, the vehicle will stop for at least "duration" seconds.
• If "duration" is 0 the vehicle will decelerate to reach velocity 0 and then start to accelerate again.
• If "until" is given and "duration" is not and the vehicle arrives at the stop at or after the time step defined by "until" it will decelerate to speed 0 and then accelerate again.
• If persons board the vehicle, the stop is extended by the "boardingDuration" of the vehicle or until the "personCapacity" is reached. (or "loadingDuration" and "containerCapacity" for containers).
• If until is defined in the context of a repeated vehicle insertion (flow) it will be incremented by the difference of vehicle creation time and "begin" of the flow.
• If neither "duration" nor "until" are given, "triggered" defaults to true. If "triggered" is set to false explicitly the vehicle will stop forever.
• if "duration" or "until" are given along with "triggered", then the vehicle will stop until the given duration/until is reached and a person has boarded
• If "parking" is set to true. The vehicle stops besides the road without blocking other vehicles.

startPos and endPos#

• by default vehicles will try to stop and the given endPos
• if the vehicle comes to a halt earlier (i.e. due to a jam) then the stop counts as reached if the vehicle front is between startPos and endPos
• if the vehicle picks up a person or container, it can do so as long as the person is between startPos and endPos
• if the stop uses attribute 'speed', than that speed will be maintained between startPos and endPos

Colors#

A color is defined as red,green,blue or red,green,blue,alpha either in a vehicle, route or vType.

<route id="r0" color="0,255,255"/>
<type id="t0" color="0,0,255"/>
<vehicle id="v0" color="255,0,0,0"/>

In the default visualization settings the vehicle color will be used if define, otherwise the type and finally the route color. These settings can be changed.

By default color components should be given as integers in the range of (0,255) but other definitions are also supported:

color="0.5, 0.5, 1.0"
color="#FF0000"
color="red"

The transparency value (alpha) only takes effect when also using the vType attribute imgFile.

Devices#

Vehicle devices are used to model and configure different aspects such as output (device.fcd) or behavior (device.rerouting).

The following device names are supported and can be used for the placeholder <DEVICENAME> below

• emission
• battery
• elechybrid
• btreiver
• btsender
• bluelight
• rerouting
• ssm
• toc
• driverstate
• fcd
• Demand Responsive Transport (Taxis)
• example

Automatic assignment#

Some devices are assigned automatically. Every <trip> that is loaded into the simulation is automatically equipped with a rerouting device to perform the initial route computation.

Other devices such as fcd are assigned automatically when the option --fcd-output is set.

Assignment by global options#

Devices can be configured globally for all vehicles in the simulation by setting the option --device.<DEVICENAME>.probability (i.e.) --device.fcd.probability 0.25 This will equip about a quarter of the vehicles with an fcd device (each vehicle determines this randomly with 25% probability) To make the assignment exact the additional option --device.<DEVICENAME>.deterministic can be set Another option is to pass the list of vehicle ids that shall be equipped using the option --device.<DEVICENAME>.explicit <ID1,ID2,...IDk>.

Assignment by generic parameters#

Another option for assigning devices for vehicle types or individual vehicles is by using generic parameters. This is done by defining them for the vehicle or the vehicle type in the following way:

<routes>
    <vehicle id="v0" route="route0" depart="0">
        <param key="has.<DEVICENAME>.device" value="true"/>
    </vehicle>

    <vType id="t1">
        <param key="has.<DEVICENAME>.device" value="true"/>
    </vType>

    <vehicle id="v1" route="route0" depart="0" type="t1"/>
</routes>