Calculate CO₂ emissions of itineraries #5278

Antiik91 · 2023-08-07T06:58:57Z

Summary

CO2 emissions information required for public transport itineraries and car journeys.
The data is loaded from a file called emissions.txt located in the gtfs package and saved to the graph during the build phase. A filter adds the emissions data to the itineraries using a service when itineraries are searched.

Issue

closes #4940

Unit tests

Tests added in a new file EmissionsServiceTest.java
Tests for:

Getting results for itinerary that has emissions data (non zero)
Getting results for itinerary that has zero emissions in the data
Not getting emission results for a feed that does not have emissions data
Getting results for a car journey

Manual testing was also performed.

Documentation

Modified:

BuildConfiguration.md
Configuration.md
Added:
DigitransitEmissions.md

Changelog

From title

…ule data fetching since the utility method was removed. Also initial unit tests added

optionsome · 2023-08-07T09:00:48Z

docs/sandbox/DigitransitEmissions.md

+
+Emissions data should be in json array with objects that have the following properties:
+
+`db`: database it refers to or CAR when referring to personal travel by car. For Example Linkki, HSL


Maybe rename this to feed_id. Although, does it necessarily match to the feed id we use for these data sets in OTP? I think we could omit this, agency_id and agency_name fields for CAR travel.

optionsome · 2023-08-07T09:08:19Z

docs/sandbox/DigitransitEmissions.md

+Emissions data is loaded from the provided source and embedded in graph building process
+as part of the itinerary.


Suggested change

Emissions data is loaded from the provided source and embedded in graph building process

as part of the itinerary.

Emissions data is loaded from the provided source and embedded into the graph during the build process.

optionsome · 2023-08-07T09:10:54Z

docs/sandbox/DigitransitEmissions.md

+
+### OTP 2.4
+
+- Initial implementation of Emissions calculation


Suggested change

- Initial implementation of Emissions calculation

- Initial implementation of the emissions calculation

optionsome · 2023-08-07T09:23:46Z

src/ext/java/org/opentripplanner/ext/emissions/DigitransitEmissions.java

Maybe we should have a package structure like package org.opentripplanner.ext.emissions.digitransit; and then these classes shouldn't have digitransit in the name. This would allow people to add other emission implementations inside the emissions sandbox. Other option would be to name this package as digitransitemissions.

optionsome · 2023-08-07T09:26:56Z

src/ext/java/org/opentripplanner/ext/emissions/DigitransitEmissions.java

+import org.opentripplanner.framework.lang.Sandbox;
+
+@Sandbox
+public class DigitransitEmissions implements Serializable {


I don't think we should load the json data into objects as such but parse it into a more sensible structure (and with more java friendly naming conventions).

optionsome · 2023-08-07T10:30:52Z

src/ext/java/org/opentripplanner/ext/emissions/EmissionsFilter.java

+  public List<Itinerary> filter(List<Itinerary> itineraries) {
+    return itineraries
+      .stream()
+      .peek(i -> {


Maybe forEach instead, I'm not too familiar with this peek method.

A old fasion loop and a return statment would make it mush easier to read - also, do not create a new list - just return the list passed into this filter. It is modifying the itineraries not to list.

optionsome · 2023-08-07T10:32:44Z

src/ext/java/org/opentripplanner/ext/emissions/EmissionsService.java

+public interface EmissionsService extends Serializable {
+  HashMap<String, DigitransitEmissionsAgency> getEmissionByAgency();
+
+  Float getEmissionsForRoute(Itinerary itinerary);


I think this should be called getEmissionsForItinerary

optionsome · 2023-08-07T10:33:14Z

src/ext/java/org/opentripplanner/ext/emissions/DigitransitEmissionsService.java

+    return null;
+  }
+
+  public Float getEmissionsForRoute(Itinerary itinerary) {


This should be the only public method in this class.

optionsome · 2023-08-07T10:50:00Z

src/ext/java/org/opentripplanner/ext/emissions/DigitransitEmissionsService.java

+@Sandbox
+public class DigitransitEmissionsService implements EmissionsService {
+
+  private HashMap<String, DigitransitEmissionsAgency> emissionByAgency;


The information we need to decide what the emissions are for a leg are agency id and transport mode. I think the key therefore could be a string of something like <feedscoped agency id>_<transport mode> and the value should be a float/double/int whatever we decide is appropriate.

Then, for car, the key could just be CAR because the agency is not relevant. Although, it could also make sense to have a special field here to store the car emission as we don't at least yet need to support emissions for other street modes.

optionsome · 2023-08-07T10:50:18Z

src/ext/java/org/opentripplanner/ext/emissions/DigitransitEmissionsService.java

+
+  private HashMap<String, DigitransitEmissionsAgency> emissionByAgency;
+
+  public DigitransitEmissionsService(DigitransitEmissions[] emissions) {


This could just take in the Map as the constructor parameter.

optionsome · 2023-08-07T11:26:38Z

src/main/java/org/opentripplanner/emissions/EmissionsConfig.java

+/**
+ * This class is responsible for mapping OSM configuration into OSM parameters.
+ */


Left over from copy paste, update.

t2gran · 2023-08-15T14:12:07Z

src/main/java/org/opentripplanner/routing/graph/Graph.java

+  public EmissionsService getEmissionsService() {
+    return emissionsService;
+  }
+
+  public void setEmissionsService(EmissionsService emissionsService) {
+    this.emissionsService = emissionsService;
+  }
+


Sorry, we do not pass "stuff" around in the graph any more, you need to inject it using Dagger.

Thanks for putting time into reviewing this draft! There are alot of changes coming soon, but you have pointed out some things I hadn't considered. I shall fix these as well before updating the pr.

Unfortunately, I'm having slight issues with the injection, as I am not sure where exactly it should be done. As far as I understand, we need to add the service/filter to the builder in RouteRequestToFilterChainMapper or ItineraryListChainBuilder, but we cannot inject anything in those. Could you maybe clarify how exactly a filter should be added without the graph? Thanks!

Take a look at the OtpServerRequestContext, witch is available where the ItineraryListFilterChainBuilder is created. You should let Dagger create your service. Then inject it in your graph-builder-module, the SerializedGraphObject and the OtpServerRequestContext. You need to inject it in the SerializedGraphObject for the data to be serialized.

I'm afraid you might have to spell this out for me, as I'm failing to see how to inject the service into the SerializedGraphObject without doing something strange. The SerializedGraphObject is initialised in the OTPMain only and I doubt you meant the emissionsservice is supposed to added to the SerializedGraphObject in the OPTMain. Also, I managed to inject and get the service from the OtpServerRequestContext, but of course it is a new instance and not the one handled during the building phase that contains the emissions data. So, I'm also failing to see how the service instance (that should be) injected into the SerializedGraphObject, will end up being the same instance that is gained from the context in the RouteRequestFilterChainMapper (as opposed to the brand new singleton without emissions data that I get now). Does there happen to be any existing service that has been implemented in the manner you are suggesting that I could maybe look at? I was only able to find the ones made in the old way and one that doesn't require the build phase at all (rideHailingService). Thanks!

I don't think there is a full example for a service, so you're breaking new ground, but the worldEnveloperRepository and dataImportIssueSummary combine data from various graph building phases and put that into the SerializedGraphObject.

OpenTripPlanner/src/main/java/org/opentripplanner/standalone/OTPMain.java

Lines 148 to 155 in bf6e4be

new SerializedGraphObject(

app.graph(),

app.transitModel(),

app.worldEnvelopeRepository(),

config.buildConfig(),

config.routerConfig(),

DataImportIssueSummary.combine(graphBuilder.issueSummary(), app.dataImportIssueSummary())

)

t2gran · 2023-08-15T14:23:54Z

.../java/org/opentripplanner/routing/algorithm/filterchain/ItineraryListFilterChainBuilder.java

+  @Sandbox
+  private EmissionsService emissionsService;


I would prefer that you set the ItineraryListFilter emissionsFilter here, not the service, so that the ItineraryListFilterChainBuilder has does not need to depend on the org.opentripplanner.ext.emissions package. I know we have a few other dependencies to the sandbox in here - because they relay on the config, but the emission seems to not have any config.

t2gran · 2023-08-21T14:43:25Z

src/ext/java/org/opentripplanner/ext/emissions/DigitransitEmissionsMode.java

+
+  private String name;
+  private float avg;
+  private int p_avg;


Underscores(C style) are not allowed in any package, class, field or variable names according to our coding guideline.

leonardehrenfried · 2023-09-01T11:25:10Z

You need to rebase on or merge the dev-2.x branch in order for the compilation to succeed.

optionsome

The issue store entries shouldn't have too generic labels as then it's hard to figure what the errors are related to when browsing through error types.

optionsome · 2023-10-31T14:01:25Z