Simulation/Rerouter

generated on 2018-12-14 00:24:44.847359 from the wiki page for Simulation/Rerouter for SUMO git

Rerouter

Rerouter changes the route of a vehicle as soon as the vehicle moves onto a specified edge.

A rerouter is set into the simulated network by adding the following declaration line to an additional-file: <rerouter id="<REROUTER_ID>" edges="<EDGE_ID>[;<EDGE_ID>]*" file="<DEFINITION_FILE>" [probability="<PROBABILITY>"]/>. Rerouter may be placed on several edges, at least one edge is necessary. Furthermore, it is possible to define the probability for rerouting a vehicle by giving a number between 0 (none) and 1 (all) already within the definition. The declaration values are:

Attribute Name Value Type Description
id id (string) The id of of the rerouter
edges float An edge id or a list of edge ids where vehicles shall be rerouted
file float The path to the definition file (alternatively, the intervals may defined as children of the rerouter)
probability float The probability for vehicle rerouting (0-1), default 1
timeThreshold time (s) minimum accumulated waiting time before the rerouter takes effect (default 0 applies always)
vTypes stringList Space-separated list of vType IDs for which this rerouter should apply (default "" applies to all)
off bool Whether the router should be inactive initially (and switched on in the gui), default:false

A rerouter may work in several different ways. Within a time period you may close an edge, or assign new destinations or predefined routes to vehicles. The next sections will describe these actions in detail.

Definition styles

There are two styles in which to declare rerouters.

everything in one file

The additional-file looks like this:

<additional>
   <rerouter id="<REROUTER_ID>" edges="<EDGE_ID>[;<EDGE_ID>]*" [probability="<PROBABILITY>"]>
       <interval begin="<BEGIN_TIME>" end="<END_TIME>">
          ... action description ...
       </interval>

       ... further intervals ...
   </rerouter>

   ... further rerouters ...
</additional>

definitions in a separate file

The additional-file looks like this:

<additional>
   <rerouter id="<REROUTER_ID>" edges="<EDGE_ID>[;<EDGE_ID>]*" file="<DEFINITION_FILE>" [probability="<PROBABILITY>"]/>

   ... further rerouters ...
</additional>

And the <DEFINITION_FILE> (which describes the actions over time) looks like this:

<rerouter>
   <interval begin="<BEGIN_TIME>" end="<END_TIME>">
      ... action description ...
   </interval>

   ... further intervals ...

</rerouter>

Note, that the name of the root-level element (<rerouter> in this case) is arbitrary.


Closing a Street

A "closingReroute" forces the rerouter to close the edge <EDGE_ID>. Vehicles which normally would pass this edge will get a new route as soon as they reach one of the edges given in the edges-attribute of the rerouter's declaration. The algorithm for selecting a new route is the same as described at #Assigning_a_new_Destination with the additional constraint that closed edges must be avoided. A closingReroute definition may look like this:

<rerouter>
   <interval begin="<BEGIN_TIME>" end="<END_TIME>">
      <closingReroute id="<EDGE_ID>"/>
   </interval>

   ... further intervals ...

</rerouter>

The attributes used within such definitions are:

Attribute Name Value Type Description
id id (string) The id of the closed edge; the id must be the id of an edge within the network
allow list of vehicle classes The (optional) ' '-separated list of vehicle classes which are still allowed to drive on the closed edge. All others are forbidden.
disallow list of vehicle classes The (optional) ' '-separated list of vehicle classes which are forbidden from driving on the closed edge. All others are allowed.

When using a <closingReroute without attributes allow and disallow, vehicles that cannot reach their destination by an alternative route simply continue on their old route and will effectively ignore the closing of the edges. When using either attribute allow or disallow (only one may be used in the same definition), vehicles which cannot change their route will stop in front of the closed edge until the defined interval ends. This may be used to simulate traffic jams, caused by spontaneous road closing.

Caution:
When using modified permissions, it may be necessary to use the option --ignore-route-errors as vehicles which are inserted while the closing is active may raise a route error otherwise. Furthermore, permissions may cause emergency braking. This can be mitigated by placing VariableSpeedSigns ahead of the closing and slowing down traffic briefly before the closing.

Closing a Lane

A "closingLaneReroute" forces the rerouter to close the lane <LANE_ID> by setting its permissions to authority (this can be customized). Vehicles that pass this route and which are equipped with a rerouting device may compute a new route as soon as they reach one of the edges given in the edges-attribute of the rerouter's declaration. A closingLaneReroute definition may look like this:

<rerouter>
   <interval begin="<BEGIN_TIME>" end="<END_TIME>">
      <closingLaneReroute id="<LANE_ID>"/>
   </interval>

   ... further intervals ...

</rerouter>

The attributes used within such definitions are:

Attribute Name Value Type Description
id id (string) The id of the closed lane; the id must be the id of a lane within the network
allow list of vehicle classes The (optional) ' '-separated list of vehicle classes which are still allowed to drive on the closed edge. All others are forbidden. (default authority)
disallow list of vehicle classes The (optional) ' '-separated list of vehicle classes which are forbidden from driving on the closed edge. All others are allowed. (This attribute may be used instead of allow for brevity if only a few classes shall be disallowed).
Note:
Modified permissions may cause emergency braking. This can be mitigated by placing VariableSpeedSigns ahead of the closing and slowing down traffic briefly before the closing.

Assigning a new Destination

A "dest_prob_reroute" forces the rerouter to assign a new route to vehicles that pass one of the edges defined in the edges-attribute of the rerouter's declaration. A new route destination is used, defined by the name of a new destination in the according element:

<rerouter>
   <interval begin="<BEGIN_TIME>" end="<END_TIME>">
      <destProbReroute id="<EDGE_ID1>" probability="<PROBABILITY1>"/>
      <destProbReroute id="<EDGE_ID2>" probability="<PROBABILITY2>"/>
   </interval>

   ... further intervals ...

</rerouter>

The fastest route is computed automatically using the Dijkstra-algorithm and starting at the edge the vehicle is located at and ending at the new destination. The following travel times are considered for routing (the first applicable value is used):

The attributes used within a dest_prob_reroute are:

Attribute Name Value Type Description
id id (string) The id of the new destination; the id must be the id of an edge within the network or one of the special values keepDestination, terminateRoute
probability float (should be between 0 and 1) The probability with which a vehicle will use the given edge as destination; the probabilities are automatically normalized to sum to 1
Note:
It is possible to combine closingReroute and destProbReroute within the same interval. In this case, only vehicles which cannot reach their original destination draw new destinations from the probability distribution.


Special Destination Values

  • keepDestination: the vehicle continues on its current route
  • terminateRoute: the vehicle immediately leaves the simulation and counts as arrived at its current position on the rerouter edge

Assigning a new Route

A "route_prob_reroute" forces the rerouter to assign a new route to vehicles which pass one of the edges defined in the edges-attribute of the rerouter's declaration. In this case, the id of a complete route must be supplied instead of a new destination:

<rerouter>
   <interval begin="<BEGIN_TIME>" end="<END_TIME>">
      <routeProbReroute id="<ROUTE_ID1>" probability="<PROBABILITY1>"/>
      <routeProbReroute id="<ROUTE_ID2>" probability="<PROBABILITY2>"/>
   </interval>

   ... further intervals ...

</rerouter>

The attributes used within such definitions are:

Attribute Name Value Type Description
id id (string) The id of a new route to assign; the id must be the id of a previously loaded route
probability float The the probability with which a vehicle will use the given edge as destination; (default 1). The probabilities are automatically normalized for all entries

Rerouting to an alternative Parking Area

Vehicles that stop at a parking area may encounter the situation that the parking area has reached the limit of its capacity and does not permit parking.

In this case the vehicle either waits on the road until a parking space becomes available or it may reroute to an alternative parking area. For the latter behaviour a parkingAreaReroute-definition must be specified. This rerouter definition defines a set of parking areas that may be mutually used as alternatives. Rerouting two another parking area is triggered in two cases:

  • when a vehicle reaches a parkingArea and is unable to stop due to lack of capacity
  • when a vehicle enters one of the rerouter-edges and the following conditions are all met:
    • it's current destination parkingArea is among the set of parkingAreaReroute definitions and has attribute visible="true"
    • it's current destination parkingArea is full

The definition looks like this:

   <rerouter id="myRerouter" edges="a b">
      <interval begin="0" end="2000">
         <parkingAreaReroute id="ParkAreaA"/>
         <parkingAreaReroute id="ParkAreaB"/>
      </interval>
   </rerouter>

The attributes used within such definitions are:

Attribute Name Value Type Description
id id (string) The id of an existing parking area
probability float The probability for each of the alternatives to be selected (default 1). The probabilities are automatically normalized over all definitions in a rerouter.
visible bool Whether occupancy of this parkingArea is known before reaching the parkingArea edge (this models line-of-sight as well as parking information systems).

Determining the alternative parking area

The alternative parkingArea will be selected among all parking areas that are visible and have at least 1 free space according to the minimum weighted sum over a number of attributes. For invisible parkingAreas (attribute visible="false", the occupancy value is a taken as a random number from [0,capacity[ which means they are always among the set of alternatives even when full. By default only the distance from the current vehicle position to the new parking area is considered. The following table describes the weighting factors that can be customized using generic parameters of the vehicle or its vType:

Parameter Name Default value Description Inverse (Bigger is better)
parking.probability.weight 0 the influence of the probability attribute of the parkingAreaReroute yes
parking.capacity.weight 0 The total capacity of the parking area yes
parking.capacity.weight 0 The total capacity of the parking area yes
parking.absfreespace.weight 0 The absolute number of free spaces yes
parking.relfreespace.weight 0 The relative number of free spaces yes
parking.distanceto.weight 1 The road distance to the parking area no
parking.timeto.weight 0 The assumed travel time to the parking area no
parking.distancefrom.weight 0 The road distance from the parking area to the vehicles destination no
parking.timefrom.weight 0 The assumed travel time from the parking area to the vehicle destination no

Destination after rerouting

Generally, vehicles that reroute to a new parking area will continue to their original destination after finishing the stop. In the special case where

  1. the original route ended at the original parkingArea edge and
  2. the arrivalPos was within [startPos, endPos] of the original parkingArea

then the new route will also end at the new parkingArea and the endPos of the new parkingArea will be set as new arrivalPos.


This page was last modified on 2 July 2018, at 08:31.