as you know PTV's routing engine enables you to deal with emission calculation. Here's a collection of URLs that could be helpful in this context:
- Sample route from Karlsruhe to Frankfurt via Mannheim. Output shows "emissions per leg" based on HBEFA 3.2 (one out of several comprehensive standards)
| Approach | comprehensive | Factor based |
|---|---|---|
| Example | HBEFA (Europe), Copert (Australia) | Cen 2012 (Europe), Defra 2014 (UK), CO² Decree 2017 (France), NGA Factors 2015 (Australia) |
| Concept | Comprehensive emission calculation approaches contain default values for fuel consumption and factors for calculation. As user no own consumption data has to be added. | Factor-based calculation approaches contain factors for emission calculation. Users have to enter their own consumption data. Default values for consumptions are provided in this use case description. |
| Elevations? | Comprehensive approaches consider the elevations, i.e. driving uphill produces output that differs from the downhill version. | Factor-based calculation approaches do not consider elevations. |
- complete route
- per leg
- per segment
- RequestBase.VehicleProfile : specify physical characteristics of a vehicle - might be relevant due to the chosen approach, e.g. the VehicleProfile.Engine.
- RouteOptions.EmissionOptions : The emissions for different fuel consumption scenarios. Only those scenarios will be returned for which the corresponding request parameter is set.
- RouteOptions.EffectiveFuelConsumptions : The attributes for calculating CEN or factor-based emissions. The response element contains only those scenarios for which the corresponding request parameter is set.
- ResultFields.Emissions. In the same way use LegResultFields and SegmentResultFields to get data on a more detailed level.
- Output: Emissions
Furthermore I recommend to care fo the following bullets:
- TourOptimization: Emission calculation is based on xRoute. It is not part of xTour or any other xServer module.
- Coverage of current standards? Though xRoute 1 supports the calculation of emissions you should be aware that newer standards such as latest HBEFA 4 or later will probably no longer be integrated into xRoute 1.
- Reporting versus Optimization: Emission calculation is proceeded AFTER the routing process itself (during the so called "listing" step), therefore it is not part of a routings target function. "Minimize emissions" is not possible by design - you may ensure to compute a short or fast track but the Emission will be derived from the calculated route.
- Detail levels: Emissions can be calculated based on a whole route, per leg or even per segment (ridiculous if you ask me). If you want to partition the emissions to the freight ("this single palette with 64 cradles of beer produced ... during its transport from Barcelona to Warszaw...together with 5t of other goods") you needd to do this on your own. There's no standard metric for this!
- Does emission calcultion consider elevations? That depends on the standard you apply: HABEFA 3.1 and COPERT consider the elevations, i.e. driving uphill differs from downhill.
- What is the difference between CO2 and CO2e? In the context of emission calculation some standards return CO2 (e.g. EmissionValueScenario_FRENCH_CO2_DECREE_2011_1336) while others mention CO2e (e.g. EmissionValueScenario_FRENCH_CO2E_DECREE_2017_639). There's a small difference between CO2 and CO2e: While CO2 completely refers to Carbon Dioxide the CO2e also considers other substances for which a so-called "equivalent" is computed. "Equivalent" means that the emitted amount of that substance produces "the same damage to the environment" than the reference volume of Carbon Dioxide. Be careful not to mix this up. You can recognize this by the name of a type or property.
PS: Feel free to check this article about CEN approaches, too. It contains an overview of the different fuel scenarios.
