Walk contains walk segment represented by distance and duration.
|distance||Yes||Integer||Distance to cover by walk|
|duration||Yes||TimeDelta||Expected time to cover that distance|
|elevator||-||Boolean||1 if elevator is present on the current station|
|escalator||-||Boolean||1 if escalator is present on the current station|
|maneuvers_id||-||Integer||Maybe used to find Maneuver element from Maneuvers element for more details about this section.|