[Q&A] Car usage increases even after introducing autonomous DRT

[numerati93]

Provide the MATSim version you are using. You can find the version in the pom.xml. E.g. 2025.0.

16.0-2024w08

Did you build a minimal example to reproduce the issue?

• Yes!

Describe the problem you are facing.

I'm using MATSim to analyze the impact of introducing autonomous DRT in a specific region.

To evaluate this, I conducted analyses with and without autonomous DRT. However, despite introducing autonomous DRT as a new transport mode, I observed an unexpected increase in private car usage.

In my setup, only car and DRT are simulated with vehicles, while other modes such as public transport, bike, and walk are handled as teleported modes. This pattern appears in both the output plan and experienced plans, so it doesn’t seem to be an issue related solely to replanning or scoring.

I suspect the issue might be related to the configuration or mode setup, especially in how MATSim handles mode choice when introducing new alternatives.

Below is my mode parameters and routing setup:

<module name="modeParams">
    <parameterset type="modeParams">
        <param name="mode" value="car"/>
        <param name="dailyMonetaryConstant" value="0.0"/>
        <param name="dailyUtilityConstant" value="0.0"/>
        <param name="constant" value="0.2"/>
        <param name="marginalUtilityOfDistance_util_m" value="-0.00005"/>
        <param name="marginalUtilityOfTraveling_util_hr" value="0"/>
        <param name="monetaryDistanceRate" value="-0.0015"/>
    </parameterset>

    <parameterset type="modeParams">
        <param name="mode" value="pt"/>
        <param name="dailyMonetaryConstant" value="0.0"/>
        <param name="dailyUtilityConstant" value="0.0"/>
        <param name="constant" value="-0.35"/>
        <param name="marginalUtilityOfDistance_util_m" value="-0.00005"/>
        <param name="marginalUtilityOfTraveling_util_hr" value="0.2"/>
        <param name="monetaryDistanceRate" value="0.0"/>
    </parameterset>

    <parameterset type="modeParams">
        <param name="mode" value="walk"/>
        <param name="dailyMonetaryConstant" value="0.0"/>
        <param name="dailyUtilityConstant" value="0.0"/>
        <param name="constant" value="0.2"/>
        <param name="marginalUtilityOfDistance_util_m" value="-0.0001"/>
        <param name="marginalUtilityOfTraveling_util_hr" value="0.2"/>
        <param name="monetaryDistanceRate" value="0.0"/>
    </parameterset>

    <parameterset type="modeParams">
        <param name="mode" value="bike"/>
        <param name="dailyMonetaryConstant" value="0.0"/>
        <param name="dailyUtilityConstant" value="0.0"/>
        <param name="constant" value="-0.2"/>
        <param name="marginalUtilityOfDistance_util_m" value="-0.0001"/>
        <param name="marginalUtilityOfTraveling_util_hr" value="0.2"/>
        <param name="monetaryDistanceRate" value="0.0"/>
    </parameterset>

    <parameterset type="modeParams">
        <param name="mode" value="drt"/>
        <param name="dailyMonetaryConstant" value="0.0"/>
        <param name="dailyUtilityConstant" value="0.0"/>
        <param name="constant" value="0.0"/>
        <param name="marginalUtilityOfDistance_util_m" value="0.0"/>
        <param name="marginalUtilityOfTraveling_util_hr" value="-0.42"/>
        <param name="monetaryDistanceRate" value="-0.0005"/>
    </parameterset>
</module>

<module name="routing">
    <parameterset type="teleportedModeParameters">
        <param name="mode" value="pt"/>
        <param name="beelineDistanceFactor" value="1.3"/>
        <param name="teleportedModeSpeed" value="7.0"/>
    </parameterset>
    <parameterset type="teleportedModeParameters">
        <param name="mode" value="walk"/>
        <param name="beelineDistanceFactor" value="1.0"/>
        <param name="teleportedModeSpeed" value="1.2"/>
    </parameterset>
    <parameterset type="teleportedModeParameters">
        <param name="mode" value="bike"/>
        <param name="beelineDistanceFactor" value="1.0"/>
        <param name="teleportedModeSpeed" value="4.0"/>
    </parameterset>
</module>

<module name="subtourModeChoice"> 
    <param name="chainBasedModes" value="car,bike"/>
    <param name="considerCarAvailability" value="true"/>
    <param name="probaForRandomSingleTripMode" value="0.5"/>
    <param name="modes" value="car,pt,walk,bike,drt"/>
</module>

Has anyone seen similar unexpected increases in other mode usage when adding DRT? What would you suggest checking in this kind of setup?

I’ve also attached the full configuration files for reference.

Thank you in advance for any insights!

If possible, provide a link to your minimal example. This might be a GitHub repository.

No response

If you want, provide some background information about you and your project. This might help us understand your issue better.

config files.zip

[sebhoerl]

How do you measure "car usage increases"?

[numerati93]

I measure increases in car usage based on mode shares. Specifically, I define mode share as the proportion of trips taken using a specific mode relative to the total number of trips.

In the scenario without autonomous DRT, I calculated mode shares using all trips. In contrast, in the autonomous DRT scenario, I excluded trips involving DRT interactions when calculating mode shares.