# Consumption model

The Routing API allows you to specify vehicle specific parameters, which are then used to calculate energy consumption for the vehicle on a given route.

Unless specified otherwise, the energy is assumed to be in Wh.

## Parameters

The following parameters define the consumption model for consumption calculation:

Parameter Description
ascent Rate of energy consumed per meter rise in elevation.
descent Rate of energy recovered per meter fall in elevation.
freeFlowSpeedTable Function curve specifying consumption rate at a given free flow speed on a flat stretch of road. See Consumption speed table for details.
trafficSpeedTable Function curve specifying consumption rate at a given speed under traffic conditions on a flat stretch of road. See Consumption speed table for details.
auxiliaryConsumption Rate of energy consumed by the vehicle's auxiliary systems (e.g., air conditioning, lights) per second of travel.

## Consumption speed table

Consumption speed tables define the energy consumption rate when the vehicle travels on a straight road without elevation change at a given speed in km/h.

A table represents a piecewise linear function. Here is an example of a function with the correrspoding request option:

### Request

ev[freeFlowSpeedTable]=0,0.239,27,0.239,45,0.259,60,0.196,
75,0.207,90,0.238,100,0.26,110,0.296,120,0.337,130,0.351


### Consumption speed function

API allows to specify two different consumption speed tables: free flow speed table and traffic speed table.

• Free flow speed table describes energy consumption when travelling at constant speed.

• Traffic speed table describes energy consumption when travelling under heavy traffic conditions, i.e. when the vehicle is expected to often change the travel speed, at a given average speed.

If trafficSpeedTable is not provided then only freeFlowSpeedTable is used for calculating speed-related energy consumption. Otherwise, the following formula is applied:

S(v_f, v_t) = S_T(v_t) + \frac{v_t}{v_f} \times (S_F(v_t) - S_T(v_t)),


where

• $v_f$ is the free flow speed of a given road, defined as estimated speed of travel without considering any traffic-related constraints,
• $v_t$ is the average traffic speed of a given road, that uses available traffic information to estimate the speed of travel,
• $S_T$ and $S_F$ are the traffic and free flow speed tables, respectively.

For example, if traffic speed is equal to the free flow speed then only the freeFlowSpeedTable will be used for determining the energy consumption, and the lower the traffic speed is compared to free flow speed, the bigger effect the trafficSpeedTable will have.

## Consumption calculation formula

E = E_{s} \cdot l + E_{a} \cdot h^+ - E_{d} \cdot h^- + E_{aux} \cdot t + E_{turn},