TraCI/Change Vehicle State

Command 0xc4: Change Vehicle State#

ubyte string ubyte <value_type>
Variable Vehicle ID Type of the value New Value

Changes the state of a vehicle. Because it is possible to change different values of a vehicle, the number of parameter to supply and their types differ between commands. The following values can be changed, the parameter which must be given are also shown in the table. Furthermore it is possible to change all values mentioned in TraCI/Change_VehicleType_State. If you do so, the vehicle gets a new type (named "typeid@vehid") and won't be affected by further changes to the original type.

Overview Changeable Vehicle Variables

Variable ValueType Description Python Method
stop (0x12) compound (string, double, byte, double), see below

Please note:

  1. The first occurrence of the edge is currently at is searched within the new route; the vehicle continues the route from this point in the route from. If the edge the vehicle is currently does not exist within the new route, an error is generated.
  2. changing the route works only if the vehicle is not within an intersection.
  3. The specified lane must lie ahead of the vehicle on its current route. The next occurence is used. Intermediate edges will count the vehicle when entering and exiting.

compound message details#

The message contents are as following:

stop (0x12)#

byte integer byte string byte double byte byte byte double byte int byte double byte double
value type compound item number (4 to 7) value type string Edge ID value type double end position value type byte Lane Index value type double Duration in seconds value type byte (optional) stop flags: (see below) value type double (optional) start position value type double (optional) Until in seconds

The stop flags are a bitset with the following additive components

- 1 : parking - 2 : triggered - 4 : containerTriggered - 8 : busStop (Edge ID is re-purposed as busStop ID) - 16 : containerStop (Edge ID is re-purposed as containerStop ID) - 32 : chargingStation (Edge ID is re-purposed as chargingStation ID) - 64 : parkingArea (Edge ID is re-purposed as parkingArea ID)

change lane (0x13)#

byte integer byte byte byte double byte byte
value type compound item number (2 or 3) value type byte Lane Index value type double Duration in seconds value type byte (optional) bool for relative lane change

slow down (0x14)#

byte integer byte double byte double
value type compound item number (always 2) value type double Speed value type double Duration in seconds

open gap (0x16)#

byte integer byte double byte double byte double byte double byte double byte string
value type compound item number (4 or 5) value type double Adapted time headway in seconds value type double Adapted space headway in seconds value type double Duration in seconds value type double changeRate value type double maxDecel value type string (optional) reference vehicle ID

This command induces a temporary increase of the vehicles desired time headway (car-following parameter tau) and specifies a minimal space headway to keep, as well. The execution is seperated into an adaptation phase, where the headways are gradually altered at the specified rate. As soon as the desired headways are established they are kept for the specified duration. Afterwards they are reset to the original value. Deactivation of the control can be achieved by sending newHeadway=duration=maxDecel=-1. The desired time headway of the vehicle is left unchanged if a value of -1 is send at the corresponding position. If -1 is sent for duration, the largest possible time is set. If -1 is sent for the maxDecel, no limitation of the induced braking rate is applied. If the optional reference vehicle ID is specified, the method does not use the current leader as a reference for the gap creation but the specified vehicle.

Note

When using the Euler integration method, the time headway control does not work properly for low speeds.

move to (0x5c)#

byte integer byte string byte double
value type compound item number (always 2) value type string Lane ID value type double Position along lane

The vehicle will be removed from its lane and moved to the given position on the given lane. No collision checks are done, this means that moving the vehicle may cause a collisions or a situations leading to collision. The vehicle keeps its speed - in the next time step it is at given position + speed. Note that the lane must be a part of the route, this means it must be either a part of any of the edges within the vehicles route or an internal lane that connects route edges. To overcome this limitation, the route can be modified prior to calling moveTo.

Note

This can also be used to force a vehicle into the network that has been loaded but could not depart due to having it's departure lane blocked.

move to XY (0xb4)#

The vehicle (the center of it's front bumper) is moved to the network position that best matches the given x,y network coordinates. The edgeID and laneIndex are compared against the original OpenDRIVE lane id when possible to resolve ambiguities. The optional keepRoute flag influences mapping as follows

- keepRoute = 1: The vehicle is mapped to the closest edge within it's existing route. If no suitable position is found within 100m mapping fails with an error. - keepRoute = 0: The vehicle is mapped to the closest edge within the network. If that edge does not belong to the original route, the current route is replaced by a new route which consists of that edge only. If no suitable position is found within 100m mapping fails with an error. When using the sublane model the best lateral position that is fully within the lane will be used. Otherwise, the vehicle will drive in the center of the closest lane. - keepRoute = 2: The vehicle is mapped to the exact position in the network (including the exact lateral position). If that position lies outside the road network, the vehicle stops moving on it's own accord until it is placed back into the network with another TraCI command.

The angle value is assumed to be in navigational degrees (between 0 and 360 with 0 at the top, going clockwise). The angle is used when scoring candidate mapping lanes to resolve ambiguities. Upon mapping the vehicle is angle set to the given value for purposes of drawing and all outputs. If the angle is set to the special TraCI constant INVALID_DOUBLE_VALUE, the angle will not be used for scoring and the vehicle will assume the angle of the best found lane. When mapping the vehicle outside the road network, the angle will be computed from the previous and the new position instead.

byte integer byte string byte double
value type compound item number (5 or 6) value type string edge ID (to resolve ambiguities, may be arbitrary) value type int lane index (to resolve ambiguities, may be arbitrary)

resume (0x19)#

byte integer
value type compound item number (always 0)

change target (0x31)#

byte string
value type string Edge ID

change route by id (0x54)#

byte string
value type string Route ID

change route (0x57)#

byte int string
value type string list number of elements Edge ID

change edge travel time information (0x58)#

This command can be sent using 4, 2, or 1 parameters. In the first form, it adds a new override of edge information to the list of existing overrides for the given vehicle, valid from begin time to end time. In the second form, it adds a new override that is valid throughout the simulation, replacing an earlier one for the same edge. In the third form, it removes as earlier override for the given edge, valid throughout the simulation.

byte int byte double byte double byte string byte double
value type compound number of elements (always=4) value type double begin time (in seconds) value type double end time (in seconds) value type string edge id value type double travel time value (in s)
byte int byte string byte double
value type compound number of elements (always=2) value type string edge id value type double travel time value (in s)
byte int byte string
value type compound number of elements (always=1) value type string edge id

change edge effort information (0x59)#

This command can be sent using 4, 2, or 1 parameters. In the first form, it adds a new override of edge information to the list of existing overrides for the given vehicle, valid from begin time to end time. In the second form, it adds a new override that is valid throughout the simulation, replacing an earlier one for the same edge. In the third form, it removes as earlier override for the given edge, valid throughout the simulation.

byte int byte double byte double byte string byte double
value type compound number of elements (always=4) value type double begin time (in seconds) value type double end time (in seconds) value type string edge id value type double effort value (abstract)
byte int byte string byte double
value type compound number of elements (always=2) value type string edge id value type double effort value (abstract)
byte int byte string
value type compound number of elements (always=1) value type string edge id

reroute (compute new route) by travel time (0x90)#

byte int
value type compound number of elements (always=0)

reroute (compute new route) by effort (0x91)#

byte int
value type compound number of elements (always=0)

speed mode (0xb3)#

This command controls how speeds set with the command setSpeed (0x40) and slowDown (0x14) are used. Per default, the vehicle may only drive slower than the speed that is deemed safe by the car following model and it may not exceed the bounds on acceleration and deceleration. Furthermore, vehicles follow the right-of-way rules when approaching an intersection and if necessary they brake hard to avoid driving across a red light. One can control this behavior using the speed mode (0xb3) command. The given integer is a bitset (bit0 is the least significant bit) with the following fields:

- bit0: Regard safe speed - bit1: Regard maximum acceleration - bit2: Regard maximum deceleration - bit3: Regard right of way at intersections - bit4: Brake hard to avoid passing a red light

Setting the bit enables the check (the according value is regarded), keeping the bit==zero disables the check.

Examples:

- all checks off -> [0 0 0 0 0] -> Speed Mode = 0 - disable right of way check -> [1 0 1 1 1] -> Speed Mode = 23 - all checks on -> [1 1 1 1 1] -> Speed Mode = 31 - run a red light [0 0 1 1 1] = 7 (also requires setSpeed or slowDown)

lane change mode (0xb6)#

The laneChangeModel discriminates four reasons to change lanes:

- strategic (change lanes to continue the route) - cooperative (change in order to allow others to change) - speed gain (the other lane allows for faster driving) - obligation to drive on the right

During each simulation step the laneChangeModel computes an internal request to change the lane or to stay on the current lane.

If an external change lane command (0x13) command is in conflict with the internal request this is resolved by the current value of the vehicles lane change mode. The given integer is interpreted as a bitset (bit0 is the least significant bit) with the following fields:

  • bit1, bit0: 00 = do no strategic changes; 01 = do strategic changes if not in conflict with a TraCI request; 10 = do strategic change even if overriding TraCI request
  • bit3, bit2: 00 = do no cooperative changes; 01 = do cooperative changes if not in conflict with a TraCI request; 10 = do cooperative change even if overriding TraCI request
  • bit5, bit4: 00 = do no changes; 01 = do speed gain changes if not in conflict with a TraCI request; 10 = do speed gain change even if overriding TraCI request
  • bit7, bit6: 00 = do no right drive changes; 01 = do right drive changes if not in conflict with a TraCI request; 10 = do right drive change even if overriding TraCI request
  • bit9, bit8:
    • 00 = do not respect other drivers when following TraCI requests, adapt speed to fulfill request
    • 01 = avoid immediate collisions when following a TraCI request, adapt speed to fulfill request
    • 10 = respect the speed / brake gaps of others when changing lanes, adapt speed to fulfill request
    • 11 = respect the speed / brake gaps of others when changing lanes, no speed adaption
  • bit11, bit10: 00 = do no sublane changes; 01 = do sublane changes if not in conflict with a TraCI request; 10 = do sublane change even if overriding TraCI request

The default lane change mode is 0b011001010101 = 1621 which means that the laneChangeModel may execute all changes unless in conflict with TraCI. Requests from TraCI are handled urgently (with cooperative speed adaptations by the ego vehicle and surrounding traffic) but with full consideration for safety constraints.

To disable all autonomous changing but still handle safety checks in the simulation, either one of the modes 256 (collision avoidance) or 512 (collision avoidance and safety-gap enforcement) may be used.

add (legacy) (0x80)#

byte int byte string byte string byte int byte double byte double byte byte
value type compound number of elements (always=6) value type string vehicle type ID (must exist) value type string route ID (must exist) value type integer depart time (ms) value type double depart position value type double depart speed value type byte depart lane

Note

Please note that the values are not checked in a very elaborated way. Make sure they are correct before sending.

If a negative departure time is set, one of the following fixed time settings will be used:

  • -1: "triggered"
  • -2: "containerTriggered"

If a negative departure speed is set, one of the following fixed speed settings will be used:

  • -2: "random"
  • -3: "max"

If a negative departure position is set, one of the following position settings will be used:

  • -2: "random"
  • -3: "free"
  • -4: "base"
  • -5: "last"
  • -6: "random_free"

Please note that giving 0 as depart position will result in the vehicle starting with its front at the begin of lane (unlike the simulation default which is the vehicle placed completely on the lane "base")

If a negative departure lane is set, one of the following lane settings will be used:

  • -2: "random"
  • -3: "free"
  • -4: "allowed"
  • -5: "best"
  • -6: "first"

If an empty routeID is given, the vehicle will be placed on an route that consists of a single arbitrary edge (with suitalbe vClass permissions). This can be used to simply the initialization of remote controlled vehicle (moveToXY).

add_full (0x85)#

byte int byte string byte string byte string byte string byte string byte string byte string byte string byte string byte string byte string byte string byte int byte int
value type compound number of elements (always=14) value type string route ID (must exist) value type string vehicle type ID (must exist) value type string depart time value type string depart lane value type string depart position value type string depart speed value type string arrival lane value type string arrival position value type string arrival speed value type string from taz (origin district) value type string to taz (destination district) value type string line (for public ttansport) value type integer person capacity value type integer person number

If an empty routeID is given, the vehicle will be placed on an route that consists of a single arbitrary edge (with suitalbe vClass permissions). This can be used to simply the initialization of remote controlled vehicle (moveToXY).

Note

Please note that the values are not checked in a very elaborated way. Make sure they are correct before sending.

remove (0x81)#

byte byte
value type byte reason

The following reasons may be given:

  • 0: NOTIFICATION_TELEPORT
  • 1: NOTIFICATION_PARKING
  • 2: NOTIFICATION_ARRIVED
  • 3: NOTIFICATION_VAPORIZED
  • 4: NOTIFICATION_TELEPORT_ARRIVED

highlight (0xc7)#

ubyte int ubyte color ubyte double ubyte ubyte ubyte double ubyte ubyte
value type compound number of items in {0,1,2,3,4,5} value type color color value type double size (radius in m.) value type ubyte maximal alpha value value type double duration (in secs.) value type ubyte type ID (allows different highlight categories)

The highlight method adds a circle of the specified size and color centered at the vehicle. The circles alpha value is animated over the specified duration (fade in and out) if a positive value is given, maxAlpha \<= 0 implies persistent highlighting without animation.

Setting Device and LaneChangeModel Parameters (0x7e)#

Vehicles supports setting of device parameters using the generic parameter setting call.

Supported Device Parameters#

  • device.battery.actualBatteryCapacity (double literal)
  • device.battery.maximumBatteryCapacity (double literal)
  • device.battery.vehicleMass (double literal)
  • device.rerouting.period (double literal, set rerouting period in seconds)
  • device.rerouting.edge:EDGE_ID (double literal, set assumed travel time for rerouting for all vehicles (where EDGE_ID is the id if a network edge). This value is overwritten at the next update interval ().
  • device.example.customValue1 (double literal)
  • has.rerouting.device ("true"): can be used to dynamically enable automatic rerouting

Caution

If the vehicles does not carry the respective device an error is returned.

Supported LaneChangeModel Parameters#

- laneChangeModel.<ATTRNAME> , (double literal): <ATTRNAME> must be one of the parameters supported by the laneChangeModel of the vehicle. i.e. lcStrategic)

Application order of traci commands and simulation step#

Step n:

  1. traci.vehicle.getPosition and traci.vehicle.getSpeed show the values from step n-1
  2. when calling traci.vehicle.moveTo the vehicle is instantly placed (and still moves in this step)
  3. vNext (the speed for this step) is computed based on the values of the previous step (traci.vehicle.setSpeed overrides this)
  4. vehicle position is updated based on vNext (either by adding vNext or by adding (vPrev + vNext) / 2 depending on the value of option )
  5. the value given to traci.vehicle.moveToXY overrides the previously computed position
  6. GUI is updated to show final state of step n, outputs like fcd-output also show this state for step n

Step n+1

This means, that the position given to moveToXY in step n will be visible in the outputs for step n whereas traci.vehicle.getPosition will always show the value from the previous step.

Vehicle insertion#

When a vehicle is added using method add or addFull it is not immediately inserted into the network. Only after the next call to simulationStep does the simulation try to insert it (and this may fail when in conflict with other traffic). The result of getIDList only contains vehicles that have been inserted into the network which means the vehicle will not be listed immediately. You can force a vehicle to be inserted instantly by calling the function vehicle.moveTo or vehicle.moveToXY after adding it to the simulation.