• Variable Speed Signs
Variable Speed Signs

One of the trigger objects that may be specified within an additional-file allows the simulation of variable speed signs. The syntax for such an object is given in the following

Definition in a single file#

<additional>
    <variableSpeedSign id="vss0" lanes="middle_0">
        <step time="0" speed="2.8"/>
        <step time="100" speed="47.22"/>
        <step time="200" speed="-1"/>
    </variableSpeedSign>
</additional>

The following attributes are used within the VariableSpeedSign element:

Attribute Name Value Type Description
id id (string) The id of the Variable Speed Signal element (user choice)
lanes ids (string list) The ids of the lanes of the simulation network that shall be affected
file string optional file in which the time and speed values are defined

Each step-element is a combination of the time the next new speed shall be set and the speed to set itself and uses the following attributes:

Attribute Name Value Type Description
time time (int) Time in which the speed will be changed
speed speed (double) New speed (if no value or a negative value is given, the speed will be reset to the original network value)

Definition with an external file#

Instead of defining the speed changes of a <variableSpeedSign> in the same file, it may also be read from a second file as follows:

<additional>
  <variableSpeedSign id="VSS_ID" lanes="LANE_IDS" file="DEF_FILE">
     <step time="<TIME>" speed="<SPEED>"/>

     ... further entries ...

  </variableSpeedSign>
</additional>

A file name can be supplied, called <DEF_FILE> within the schema above. This file must contain the information about when a certain speed shall be set onto the lane. This file has the following format:

<vss>
  <step time="<TIME>" speed="<SPEED>"/>
  <step time="<TIME>" speed="<SPEED>"/>

  ... further entries ...

</vss>

Examples for variableSpeedSign definitions can be obtained from our test suites